Bulletin  Ni\  25    New  Series. 

U.  S.  I)K]\\RTiMl{N T  Oi^    ACiRiCUiyrURK. 
DIVISION  OF  kntomoi.o<;y. 


NOTES 


nf\p 


>>' 


THE  MOSQUITOES  OF  THE  UNITED  STATES 


GIVING  SOME  ACCOUNT  OF  THEIR  STRUCTURE  AND  BIOLOGY, 
WITH  REMARKS  ON  REMEDIES. 


BY 


L.  O.  HOWARD,  Vw.  W 


f-^^^ 


££^s;t5rH  ' 


WASHINGTON: 

GOVERNMENT    PRINTING-  OFFICE. 
1900. 


Bulletin  No.  25— New  Series. 


U.  S.  DEPARTMENT  OV   AC;RICULTURE. 

DIVISION    OF    KNTOMOLOGY. 


NOTES 


ON 


THE  MOSQl]ITOES  OF  THE  UNITED  STATES 

GIVING  SOME  ACCOUNT  OF  THEIR  STRUCTURE  AND  BIOLOGY. 
WITH  REMARKS  ON  REMEDIES. 


BY 


L.   O.  HOWARD,  Ph.   D. 

Entomologist. 


WASHINGTON: 

GOVERNMENT    PRINTING    OFFICE. 
1900. 


DIVISION  OF  EXrOMOLOGY.  j 

EutomologlKt:  L.  O.  Howard.  * 

7*7 />V  Asftistant  Entomologist:  C.  L.  Marlatt.  : 

Asfiiatant  E)itomologi.<its:  Th.  Pergande,  F.  II.  Chittenden,  Frank  Benton.  ' 

Inveatigntorx:  E.  A.  Sohwarz,  1).  W.  Coquillett.  ■ 
Amstantx:  R.  S.  Clifton.  Nathan  Bank^!',  F.  C  I'ratt,  Aug.  lUiyck,  Otto  Ileidemann,        j 

A.  N.  Caudell,  J.  Kotinsky.  j 

Artist:  Mii<s  L.  SulHvan.  « 
2 


LETTER  OF  TRANSMITTAL. 


U.  S.  Department  of  Agriculture, 

Division  of  Entomology, 
Was/iinc/ton,  D.  C,  July  ^^,  1900. 
Sir:  I  have  the  honor  to  transmit  herewith  manuscript  of  a  bulletm 
on  the  mosquitoes  of  the  United  States,  which  gives  some  account  of 
their  structure  and  biology  and  indicates  the  diiferences  in  all  stages 
of  existence  between  the  kinds  of  mosquitoes  which  have  been  shown 
to  transmit  malaria  and  those  which  do  not.  It  also  treats  of  the  sub- 
ject of  remedies  in  considerable  detail.  It  has  been  written  mainly 
from  the  popular  standpoint,  although  scientific  details  of  structure 
and  classification  have  been  inserted  for  the  use  of  ph3\sicians  engaged 
in  studying  malaria.  I  recommend  that  it  be  published  as  Bulletin  No. 
25,  New  Series. 

Respectfully,  L.  O.  Howard, 

Entomologist. 
Hon.  James  Wilson, 

Secretary  of  Agriculture, 

2 


INTROIUKTIOX. 


A  number  of  articles  and  notes  concern i no-  mosquitoes  have  been 
published  in  ditt'erent  bulletins  of  this  Division.  The  most  extensive 
was  the  leading  article  in  Bulletin  No.  4,  New  Series  ("The  Principal 
Household  Insects  of  the  United  States''),  and  constituted  the  larger 
part  of  chapter!,  on  ''Mosciuitoes  and  Fleas."  In  this  treatment  of 
mosquitoes  the  complete  life  history  of  C i ilex  pun  f /ens  was  given,  based 
upon  original  o])servations  made  in  the  summer  of  1895,  and  some  gen- 
eral remarks  on  the  subject  of  other  species  were  brought  together. 
Four  pages  were  devoted  to  the  subject  of  remedies,  and  the  mosquitoes 
of  the  (H)untry  at  large  were  tabulated,  with  such  notes  on  geogi'aphical 
distriljution  as  could  ))e  l)rought  together.  The  earlier  notes  pub- 
lished by  the  Division,  including  those  extracts  from  correspondence 
and  general  notes  which  had  been  published  in  the  seven  A^olumes  of 
Insect  Life,  and  the  writer's  two  articles  on  the  use  of  kerosene  against 
mosquito  larvae,  were  all  digested  in  this  bulletin,  which  was  published 
in  the  summer  of  1896.  Subsequent  brief  notes  on  remedies  have  been 
published  l)y  the  writer  in  miscellaneous  bulletins  of  the  Division  and 
in  the  Scientilic  American,  and  the  life  history  of  Anojjheles  ([uadrima- 
culatus  was  described,  in  comparison  with  that  of  Cale.i'  jmiigenH,  in  a 
short  illustrated  article  in  the  Scientitic  American  for  eluh"  7,  1900. 

The  writer  first  became  interested  in  mosquitoes  thirty  years  or 
more  ago,  Avhen  as  a  boy  he  fished  and  collected  insects  in  the  marshes 
at  the  head  of  Cayuga  Lake,  New  York,  and  as  early  as  1867  had 
experimented  with  the  kerosene  remedy  against  mosquito  larva?  in  a 
horse  trough  at  Ithaca.  In  1881  he  discussed  with  Dr.  A.  F.  A.  King  and 
the  late  C.  V.  Riley  the  l)earings  of  the  theory,  which  Dr.  King  was 
the  first  to  bring  forward  in  the  United  States,  of  the  probable  rela- 
tion between  mosquitoes  and  malaria,  both  Dr.  Riley  and  the  writer 
contending,  it  must  be  confessed,  that  the  arguments  brought  forward 
h\  Dr.  King  in  conversation  were  leased  upon  coincidental  observations, 
and  afforded  no  good  proof  of  cause  and  effect. 

The  writer's  practical  demonstration  in  1894  of  the  value  of  the 
kerosene  treatment  as  a  practical  large-scale  remedy  attracted  consid- 
erable attention  to  the  subject  of  remedies  for  mosquitoes,  and  man}^ 
large-scale  experiments  were  made,  some  of  them  being  successful  to 
a  marked  degree,  as  will  be  pointed  out  later  in  the  section  on  rem- 
edies.    The  services  of  the  members  of  this  office  force  were  called 

5 


into  n'ijuisition  on  a  number  of  occixsions  to  (Ictennino  acluiil  brooding 
points  in  niosijuito-infcstod  regions,  and  interest  in  the  subjeet  gmd- 
ually  increased  until,  during  the  past  two  or  three  years,  the  researches 
of  th<>se  medical  nu'ii.  whose  names  have  since  liecome  so  well  known 
in  this  ((Mincction,  showed  hy  exact  methods  that  Dr.  King's  theory 
nui>t  IK)  longer  b«'  considered  u  theory  but  a  demonstrated  fact.  It 
has  resulte<l  that  the  attention  of  the  entire  civilized  world  has  l>een 
drawn  with  vivid  interest  toward  the  wh(>le  mosquito  question.  Ever}' 
fact  <(nicerningmos(piitoes  becomes  now  of  great  potential  importunce. 
The  correspoiuh'nce  of  this  office  on  moscjuitoes.  owing  largely  to  its 
publications,  has  become  greatly  increased.  The  writer  has  been 
invit«'(l  to  address  scientific  bodies  and  citizens'  improvement  associa- 
tions on  the  subject  of  mos(juito  extermination,  and  in  the  spring  of 
tlu'  present  year  lectured  before  the  annual  meeting  of  the  Koyal 
Society  of  (  anada  and  ])efore  the  section  on  theory  and  practice  of 
medicine  of  the  American  Medical  Association  on  the  subject  of  the 
])iol()gy  of  the  moscjuitoes  of  the  genus  Anopheles  as  contrasted  with 
that  of  the  moscputoes  of  the  genus  Culex.  The  demand  for  the  pub- 
lications of  this  Division  on  mosquito  subjects  has  been  so  great  that 
it  has  been  deemed  desirable  to  bring  together  the  published  and 
unpublished  articles  and  notes  in  convenient  reference  form  from  the 
standpoint  of  the  liiited  States  only,  and  this  has  been  done  in  the 
prt  sent  bulletin. 

The  writtu-  is  inde))ted  to  his  assistants,  Mr.  D.  W.  Coquillett,  for 
determinations  of  the  diti'erent  mosquitoes  discussed;  Mr.  F.  C.  Pratt, 
for  untiring  efforts  in  the  collection  of  material;  Mr.  August  Busck, 
Mr.  K.  S.  Clifton,  and  Mr.  J.  Kotinsky.  for  assistance  in  laboratory 
ex])eriments,  and  Miss  L.  Sullivan,  for  the  preparation  of  the  illustra- 
tions. Information  and  specimens  derived  from  many  correspondents 
are  acknowledged  in  the  pages  of  the  bulletin. 

L.  O.  H. 


CONTENTS. 


Page. 

On  mosquitoes  in  irenoral 9 

Abundance  of  mosquitoes *> 

Alaskan  and  other  far-northern  mosquitoes 10 

Length  of  Hfe  of  the  adult  mosquito 11 

Life  history  of  mosquitoes  in  general 12 

Food  of  adult  mosquitoes 12 

How  far  will  mosquitoes  fly? 13 

Carriage  of  mosquitoes  by  railway  trains 14 

How  long  can  the  larvae  live  out  of  water? 15 

The  number  of  species  of  mosquitoes 17 

Mosquitoes  and  malaria 17 

Synoptic  tables  of  the  North  American  mosquitoes 18 

Generic  synopsis 19 

Genus  Culex 19 

(a)  Eecognized  species 19 

(b)  L'nrecognized  species 20 

Genus  Anopheles 21 

(a)  Recognized  species 21 

(b)  Unrecognized  species 21 

Genus  Psorophora 22 

Genus  ]\Iegarhinus 22 

Genus  Aeies 22 

The  biology  of  Culex,  with  remarks  on  some  of  the  species 22 

Life  history  of  Culex  pungens 22 

Remarks  on  other  species  of  Culex 28 

The  distribution  of  the  species  of  Culex  in  the  United  States 29 

The  biology  of  Anopheles,  with  general  remarks 31 

Life  history  of  Anojjheles  quadrimacidatus 32 

The  adult 32 

Resting  position 33 

Xote  of  female 34 

The  eggs 35 

The  larva 36 

The  pupa 40 

Natural  breeding  places  of  Anopheles 41 

Other  species  of  Anopheles 43 

Distribution  of  the  species  of  Anopheles  in  the  L'nited  States 44 

The  genus  Psorophora 45 

The  genus  Megarhinus 47 

The  genus  Aedes 47 

The  natural  enemies  of  mosquitoes 48 

Remedies  against  mosquitoes 49 

Remedies  in  houses  and  iirevention  of  bites 49 

Remedies  for  bites 51 


8 

Page. 

iV.wtruotion  of  larvn-  ami  alM»lition  ..f  l.rrt>«rm^  jjlaoes 51 

KtTosnn'  «in  l»n-«Mlin;.'  ixuds 51 

I  )iaiiiagt* 53 

IVa(ti«al  UK'  ..f  lisli 54 

ArtiJu'ial  :i^itati<ni  <»t  tin*  water 54 

I.at<'r  us**  « tf  ktn  istMU' 55 

OthtT  larvifitlt's 57 

l***riuaiigauatc  of  i»(4a>;li  ...                                                      57 

I'roprit'tary  iiiixturi'S 5M 

KxiKTiiiu'iits  of  (\*Hi  ari<l  CaHiigraiuli 58 

Tar  ami  itH  toiii|M»iiii<ls 60 

Kiualyi»lusln*»'s 62 

l)niiiiajz«'  and  «<»iiiiimnity  work 63 

A|»|M*inlix 66 


LUSTRATIONS. 


Pagt 


Fi<;.    1.  ('nk'X  piingen^i:  Eggs  and  vom>«r  larva' 

2.  CuK'x  ]>iingfiis:   lli-ad  and  nioiith  jiarts  of  larva 

.'>.  C'ulex  jxingt'HH:  Full-grown  larva  and  i>uj)a 

4.  CuK'X  ])ungens:  Adults,  mak' and  ft'iiiah',  with  structural  details 

').   CuK'X  ta-niofliynchus:  Female 

(>.   Anojiludes  (juadriinaculatus:  Adult  male  and  female 

7.   Resting  i>ositiuns  of  Culex  and  Anopheles  eomparetl 

Resting  positions  of  Anopheles  on  vertical  and  horizontal  walls 

Resting  i)ositions  of  Anopheles  an<l  Culex,  after  Waterhouse 

Anoi)heles  (piadrimaculatus:  Egg  mass 

Anoi)heles  (juadrimaculatus:  Isolated  eggs  from  al)Ove  and  l^elow 

Anopheles  (piadrimaculatus:  Newly  hatched  larva' 

IIalf-gr»»wn  larvje  of  Anopheles  (juadrimaculatus  contrasteil  with  same 
stiige  of  Culex  jmngens 

Feeding  jiosition  of  larva  of  Anopheles  (juadrimaculatus  contrasted 
with  that  of  Culex  jiungens 

Anoi>heles  (juadrimaculatus:  Full-grown  larva,  showing  head  from 
ahove  and  below 

Anojyheles  (juadrimaculatus:  Fujta  contrasted  with  that  of  Culex 
pungens  

Anopheles  punctij)ennis:  Head  of  full-grown  larva  fr(»m  alv)ve 

Anoplieles  j)unctii)ennis:  Adult  female 

Ano]>heles  crucians:  Adult  female 

Psorophora  ciliata:  Adult  female 

Megarhinus  rutilus:  Adult  female 

Aedes  sapphirinus:  Adult  female 


8. 

9. 
10. 
11. 
12. 

i::' 

14. 

ir>. 

k;. 

17. 
IS. 

19. 

20. 

21. 


23 
24 
26 
27 
28 
32 
33 
34 
34 
35 
35 
36 

37 

38 

39 

40 
41 

4:; 

44 
45 
4() 
47 


NOTES  ON   THE  MOSOUITOES  ()!•   THE   UNITlil) 

STATES. 


ON   MOSQUITOES   IN    (iENERAL. 

Ahimdance  of  rno^quitoe^. — The  literaturo  of  popular  cntomolooy  is 
full  of  iiLstances  of  the  enormous  numbers  in  which  mosquitoes  occa- 
sionally occur.  Persons  interested  in  this  line  of  curious  reading 
should  consult  Kirby  and  Spence's  An  Introduction  to  Entomology, 
Volume  1.  pages  112-120,  and  Frank  Cowan's  Curious  Facts  in  the 
History  of  Insects,  pages  278-286.  Referring  to  their  occurrence  in 
the  far  northern  regions,  Kirby  and  Spence,  for  example,  say:  "In  Lap- 
land their  numf)ers  are  so  prodigiou.s  as  to  be  compared  to  a  flight  of 
snow  when  the  flakes  fall  thickest  or  to  the  dust  of  the  earth.  The 
natives  can  not  take  a  mouthful  of  food  or  lie  down  to  sleep  in  their 
cabins  unless  the}^  be  fumigated  almost  to  sutiocation.  In  the  air  you 
can  not  draw^  your  breath  without  having  your  i»outh  and  nostrils 
filled  with  them,  and  unguents  of  tar,  fish  grease,  or  cream,  or  nets 
steeped  in  fetid  birch  oil  are  scarcely  sufficient  to  protect  even  the  case- 
hardened  cuticle  of  the  Laplander  from  their  bite."  Elsewhere  the 
same  authorities  say:  ''In  the  neighborhood  of  the  Crimea  the  Russian 
soldiers  are  obliged  to  sleep  in  sacks  to  defend  themselves  from  the 
mosquitoes,  and  even  this  is  not  a  sufficient  security,  for  several  of 
them  die  in  consequence  of  mortification  produced  by  the  bites  of  these 
furious  bloodsuckers."  Elsewhere:  "And  Captain  Stedman,  in  Amer- 
ica, as  a  proof  of  the  dreadful  state  to  which  he  and  his  soldiers  were 
reduced  by  them,  mentions  that  thev  Avere  forced  to  sleep  with  their 
heads  thrust  into  holes  made  in  the  earth  with  their  bayonets  and 
their  necks  wrapped  round  with  their  hammocks."  Humboldt  says: 
"Between  the  little  harbor  of  Higuerote  and  the  mouth  of  the  Rio 
Unare  the  wretched  inhabitants  are  accustomed  to  stretch  themselves 
on  the  ground  and  pass  the  nights  buried  in  the  sand  3  or  ^  inches 
deep,  leaving  out  the  head  only,  w^hich  the}^  cover  with  a  handker- 
chief." Theodoretus  saj^s  that  Sapor,  King  of  Persia,  was  compelled 
to  raise  the  siege  of  Nisibis  b}^  a  plague  of  gnats,  which  attacked  his 
elephants  and  beasts  of  burden  and  so  caused  the  rout  of  his  army. 

In  modern  times  nearly  every  hunter  and  fisherman  in  this  country 
has  had  experience  with  mosquitoes  which  renders  easy  of  belief  all 
of  the  old-time  stories.     The  instance  mentioned  in  Bulletin  No.  4,  of 

y 


10 

tho  ()))S('rvsitions  ])y  Mr.  St'hwiuz,  of  this  office,  at  Corpus  Christi, 
Tfx.,  could  l)c  practicjilly  tluplicjitcd  ))y  uiany  persons.  He  showed 
that  when  th«'  wind  })h)ws  from  any  other  direction  than  south  ''  hun- 
dreds of  thousands  of  millions"  of  moscjuitoes  l>h)W  in  upon  the  town. 
Great  heids  of  hundreds  of  horses  i*un  hefoi-e  the  mosipiitoes  in  order 
to  get  to  the  uatri .  W'itli  a  chanj^t^  of  wind,  however,  the  mosquitoes 
bh^w  away.  Many  rt'oions,  especially  alon*»'  the  seacf)ast,  have  been 
actually  i-ciidcred  uiiinlialntahle  liy  the  abundance  of  mosijuitoes,  and 
they  li:i\«'  IxMii  a  serious  draw}>ack  to  the  settlement  of  many  other- 
wis«'  ad\  aiita«^cous  and  fertile  localities. 

I)r.  Otto  Luii'i'er  rc})oi'ts,  on  patres  tilO,21T  of  iiis  annual  rt'port  for 
18JM)  as  «'Mtouioloti-ist  to  the  Minnesota  State  Ag-ricultural  Kxperiment 
Station,  an  interestinti"  sci'ies  of  ol)s«'rvations  to  det<'rmine  the  number 
of  mos(juito('s  which  may  be  bred  in  an  ordinary  rain  barrel.  The 
obsi'iN  ations  nncic  made  at  St.  Anthony  Paik.  Minnesota.  On  July  0, 
181K),  the  watc'r  in  one  barr»d  was  filtered  and  was  found  to  contain 
17,!i51*  egtrs,  larva',  and  pupa'.  On  July  :i'2^  Isi)*;,  by  a  similar  proc- 
ess, lt*,ll(l  mosijuitoes  were  counted.  When  we  consider  that  at 
least  twelve  generations  may  breed  in  a  summer  it  is  obvious,  from 
Dr.  Luggers  accoimt,  tliat  a  neighborhood  may  be  well  supplied 
from  one  neglected  rain-water  barrel. 

Ahtshui  (1 11(1  other  f (I r  tKN'th^rn  in(tsq}i!to<x. — Since  the  opening  up 
of  the  gold  fields  in  Alaska  and  the  great  influx  of  miners  and  traders, 
knowledge  of  the  abundance  and  ferocity  of  the  Alaskan  mosquitoes 
has  become  widespread,  and  surveying  parties  from  the  United  States 
Coast  and  Oeodetic  Survey  and  the  UniUnl  States  Geological  Surve\^ 
in  starting  for  Alaska  for  their  sunuiier\s  work  are  in  the  habit  of  con- 
sulting this  office  for  the  best  remedies  for  mosquito  bites.  Those 
who  were  in  Alaska  the  preceding  year  always  state  that  they  never 
experienced  or  even  imagined  anything  in  the  mosquito  line  quite  equal 
to  those  found  in  our  northern  territory.  Mr.  AV.  C  Henderson,  of 
Philadelphia,  who  spent  some  time  in  Alaska  recently,  writes:  ''They 
existed  in  countless  millions,  driving  us  to  the  verge  of  suicide  or 
insanity."  Nothing  has  as  yet  been  pu))lished  regarding  the  exact 
species  found  in  Alaska,  ))ut  Mr.  Co({uilleft  has  determined  CuJt-.r  cofi- 
snh?'/ /nts  iind  Cff/u'  ////y>/V/r/' from  specimens  collected  by  Prof.  Trevor 
Kincaid  on  the  Ibirriman  exi)edition  of  ISt)}).  0.  crmsithi'lnus  was 
collected  at  Sitka  June  hi.  and  Yakutat  June  21:  and  (\  J//tjfi(/rr  Vi^BS 
taken  at  Sitka  June  1(),  Vakutat  ,June  iM,  Virgins  Hay  June  2tK  and 
Popotl"  Island  July  S-U\. 

That  the  knowledge  of  the  existiMice  of  moscjuitoes  in  boreal  regions 
is  not  new  is  shown  by  the  (juotation  just  made  from  Kirby  and  Spence, 
and  in  Bullet iri  No.  4  the  writer  mentioned  some  of  the  instances  of 
record  by  arctic  exploi'ers,  citing,  for  exanqJe,  the  narrative  of  C.  F. 
Hair^  second  arctic  expedition,  in  which  the  stiitement  is  made  that 


11 

mosquitoes  appoarod  on  tho  7th  of  July.  1S01>,  'm  extraordinary 
abundanrc.  and  of  Dr.  K.  Storlint^,  of  C'l('\(dand,  Ohio,  who  sent  us  an 
aeeount  of  the  appeanmee  of  mosqaitoes  ])y  thousands  in  ]Mareli,  1S44, 
when  lie  was  on  a  snowshoe  trip  from  Mackinaw  to  Sault  Ste.  !Marie. 
Their  extraordinary  appearance  at  that  si»ason  of  the  ycMir  was  remark- 
able as  indicating-  a  most  plentiful  hibernation.  Mr.  II.  Stewart,  of 
North  Carolina,  was  also  cpioted  as  noticing,  on  the  north  shore  of 
Lake  Superior,  in  18r»(),  in  the  warm  days  of  ^larch,  when  the  snow^  was 
several  feet  deep  and  the  ice  on  the  lake  T)  feet  in  thickness,  that  mos- 
quitoes appeared  in  swarms,  "literally  blackening  the  banks  of  snow 
in  the  sheltered  places."  Dr.  Otto  Lugger  was  also  ipioted  as  stating 
that  Calex  coiisohrhim  made  its  appearance  in  April,  1896,  at  St. 
Anthony  Park,  Minnesota,  in  a  genuine  swarm  with  a  heavy  snow-- 
storm, at  a  time  w^hen  all  the  lakes  w^ere  covered  with  ice. 

Dr.  Lugger  has  also  called  the  w  riter's  attention  to  the  fact  that  Dr. 
Emile  Bessels,  of  the  Polaris  expedition,  was  obliged  to  interrupt  his 
w^ork  in  Davis  Straits  (latitude  72'-*  N.)  on  account  of  the  multitude  of 
these  insects. 

Length  of  life  of  the  adult  mosquito. — A  curious  and.  as  yet  unex- 
plained point  in  regard  to  a  phase  of  mosquito  existence  is  their  extra- 
ordinary abundance  at  certain  times  upon  dry  prairies  miles  from  water,- 
which  has  led  to  the  very  generally  accepted  idea  among  far  Western- 
ers that  all  mosquitoes  do  not  need  pools  of  stagnant  Avater  in  which  to 
breed,  ])ut  that  certain  of  them  must  have  some  other  breeding  habit. 
This  supposition  still  appears  incredil)le  to  the  Avriter,  who  is  much 
more  inclined  to  attriliute  this  abundance  in  drv  reo-ions  to  a  o-reater 
longevity  on  the  part  of  the  adult  mosquitoes  of  certain  species  than 
has  been  proven,  thus  ena])ling  these  great  swarms  to  live  from  one 
rainy  spell  to  another,  no  matter  how^  widelv  separated.  The  gravid 
females  of  most  insects  seem  to  be  able  to  live  until  they  have  oppor- 
tunity^ for  appropriate  oviposition.  The  writer  is  frequently  asked  as 
to  the  duration  of  the  adult  stage  of  mosquitoes,  but  bevond  the 
statement  that  although  adults  hibernate,  living  in  this  condition  from 
November  until  April  or  May  in  the  latitude  of  Washington,  he  is 
obliged  to  state  that  thev  die  rather  quickh^  in  conlinement  in  the 
summer.  He  has  had  living  specimens  of  Anopheles  quadrimaculatus 
confined  in  breeding  jars  for  eight  da^^s,  all  dying,  however,  at  the 
expiration  of  that  time.  Dr.  Woldert  has  kept  adults  for  fifteen  days 
in  a  wide-mouthed  bottle  in  which  was  placed  a  small  slice  of  banana, 
the  gauze  with  which  the  bottle  w^as  covered  being  sprinkled  ever}^ 
day.  Other  specimens  were  kept  from  fifty  to  sixty  days,  but  this 
was  in  the  late  fall,  and  many  of  them  would  probabh^  have  hiber- 
nated. Dr.  ]Manson  states  that  they  ma}^  be  kept  for  wrecks  in  a  glass 
vessel  containing  a  piece  of  ripe  banana,  the  banana  being  renewed 
everj^  three  or  four  days. 


n 


Lit'  Jus/urij  nf'  iiiostjuitiHs  in  i/«  IK  /'III.  Ill  *,'"('iH'l*al  U'l'IUs  lh<»  hiologV 
of  till'  Curniilu'  -tlio  fjiinily  to  which  the  tnu'  iM(>s<|uitoes  In'lontr — 
may  luiflly  Im'  sninnuHl  iij).  All  j^n'iicral  >tat«'iin'iit>  luTctoforo  have 
Imm'ii  l»asr(l  ujmmi  tlir  life  history  of  oiu'  or  two  sju'cics  of  thi*  ji'iMuis 
Ciih'x.  \v{  it  is  ccitaiii  that  such  remarks  will  not  only  not  hold  for 
the  whoh'  family,  hut  that,  except  in  a  general  way.  tlicy  will  not  hold 
foi-  all  the  species  of  ( 'iih'X.  So  fa?-  as  is  detinitely  known,  the  larva* 
of  all  m<)S(juit(Hvs  ar«'  aqnati<'.  althouji'h  they  an'  tiin'  air  hreatht'rs; 
that  i-  (()  say.  tlicy  iiiii>t  <'<>mc  to  the  surface  {\i  the  water  to  hreathe. 
Tiny  ar;-  ra})i(l  liiceders  and  })ass  the  pupal  condition  also  in  water, 
hut  tloatin<^-  normally  at  the  surface.  They  pa>s  throujrh  several  «^en- 
erations  in  tin*  <ourse  of  a  year  and  hihernate  as  adults.  Hihernatint( 
iiios(juitoes  juay  fieijuenlly  ))e  found  durini,'  the  winter  months  in 
harns  and  in  the  cellai's  and  cold  «:arrets  of  houses.  Dr.  W.  S. 
Thayer,  of  Haltimore.  informs  the  wi-iter  that  he  found  Antfph^^lex 
rrnciiins  and  .1.  tjinnlr/ iiKicuhifus  hihernatini^  in  <'norinous  nund>ers  in 
harns  near  New  Orleans,  clusterin^^  umU'r  the  roofs  and  on  the  walls. 
In  the  exti'eme  Southern  States  many  mos«|uitoes  are  activi' all  throu»>"h 
the  winter,  and  moscjuito  hars  ar«'  almost  as  necessary  at  Christnuis 
time  as  <lurin*:-  the  sununer. 

yuitil  fif  adult  innHij^ii'itiHs.  —  It  is  a  well-known  fact  that  the  adult 
mal(*  mosijuito  does  not  necessarily  take  nourishment  and  that  the 
adult  female  does  not  necessarily  rely  on  the  blood  of  warm-hlooded 
animals.  The  mouth  parts  of  the  male  are  so  diti'erent  from  those  of 
the  female  that  it  is  probable  that  if  it  feeds  at  all  it  obtains  its 
food  in  a  quite  ditienMit  manner  from  the*  female.  They  are  often 
observed  sipping-  at  drops  of  water,  and  in  one  instance  a  fondness 
for  molasses  has  been  recorded. 

Tln'  writer  has  already  placed  on  record  the  instance  in  which  his 
eolleatrue,  Mr.  E.  A.  Schwarz,  observed  a  male  moscjuito  si})ping  beer, 
but  \\w  most  inteii'stini^  instance  of  alcoholism  of  the  male  mosquito 
which  has  come  to  his  notice  was  described  in  a  letter  icceived  last 
sprinu-  from  l)r.  St.  (b^or^-e  Gray,  of  Castries,  St.  Lucia,  British 
West  Indies.      I)r.  (iray  wrote: 

"The  inales,  especially  (\  pipimtif  are  very  f(»n(l  <»1  wine,  ami  almost  every  day  I 
can  cat<h  one  (»r  two — always  males — on  the  neck  of  the  cltH-anter  or  in  a  wineglass 
that  hiLs  just  l>eeii  used.  I  jmt  a  few  mosquitoes  under  a  1k?11  jar  one  day  in  order  to 
watch  them.  I  j»ut  a  single  drop  of  port  wine  under  the  jar,  iis  I  had  heard  that 
mMS(|uitoes  could  1k'  k«'j>t  alive  for  a  lung  tinje  on  wine.  When  I  went  to  look  at 
them  a  few  luairs  later  I  found  them  all  api>aivntly  dea«l,  so  I  put  them  in  a  <lry 
iMjttle,  intending  to  i>in  them  later.  When  I  went  to  pin  them  shortly  afterwanls 
they  were  all  staggering  aliout  in  the  most  ridiculous  manner — they  weiv  drunk!" 

The  female  moscjuitoes  ar«'  normally  without  nmch  doubt  plant 
feeders.  Why  they  should  draw  blood  at  all  is  a  (|uestion  which  has 
not  been  sohed.      It  lias  l»een  >urmised  that  a  >ui)ply  <d'  hiirhly  nutri- 


18 

tivo  tluid  is  nr/oss;iiT  tor  tlic  foiination  of  the  cj^'^r^,  Imt  lliis  sn])|)()si- 
tioii  is  at  once  (Miiphatically  iiouativcd  by  tiio  fact  that  mosfjiiitocs 
a})Oiuul  in  reg-ions  into  which  wanii-hjoodcd  animals  ncvci-  ])cnctrato. 
The  statement  which  the  writiM-  has  (Mscwlicic  made,  tliat  not  one  in  a 
million  ever  oots  the  opportunity  to  taste  tlic  blood  of  a  warm-blooded 
animal,  is  unipiestionably  an  un(lerestimat(\  There  are  in  this  counti-y 
enormous  tracts  of  marshy  hind  into  whidi  warm-])lo()(l('(l  animals 
never  tind  their  way  and  in  which  mos(piitoes  are  breedino-  in  count- 
less numbers,  and  when  we  ovt  within  the  Arctic  Circle^  and  other 
uninhabit(Ml  regions  the  point  is  emphasized.  Scattered  through  the 
seven  volumes  of  Insect  Life  are  records  of  the  observation  of  the 
vegetarian  habit,  one  writer  stating  that  he  has  seen  mosquitoes  with 
their  beaks  inserted  in  boiled  potatoes  and  another  that  he  has  seen 
waternudon  rinds  with  man}'  mosquitoes  settled  upon  them  busily 
engaged  in  sucking  the  juice.  That  they  may  and  occasionally  do 
feed  upon  other  than  warm-blooded  animals,  however,  is  evidenced 
by  an  observation  by  the  late  Dr.  IT.  A.  Hagen,  who  mentions  taking 
a  species  of  mosquito  in  the  Northwest  which  was  engaged  in  feeding 
upon  the  chrysalis  of  a  butterfly ,  while  there  are  several  instances  on 
record  where  they  have  been  observed  puncturing  the  heads  of  young 
fish  and  killing  them. 

IIov)  few  v:lll  rnosquitocs  JJy? — The  cpiestion  is  often  asked:  "How 
far  will  mosquitoes  fly  from  their  breeding  places,  or  how  far  can  the}^ 
be  driven  l)v  the  wind  i ''  In  some  instances  this  becomes  a  matter  of 
practical  importance,  since,  if  mosquitoes  fly  great  distances,  extermi- 
native  work  on  the  lireeding  places  near  a  house  or  comnumity  will  be 
of  comparatively  slight  avail.  There  exists  on  this  point  a  difl'erence 
of  opinion.  In  a  discussion  at  the  meeting  of  the  Association  of  Eco- 
nomic Entomologists  at  Boston,  in  August,  1808,  Dr.  John  B.  Smith 
stated,  in  referring  to  the  possibility  of  mosqidtoes  l)eing  carried  In^ 
strong  winds  to  considerable  distances,  that  he  had  noticed  that  they 
would  not  rise  or  take  flight  when  a  brisk  breeze  was  blowing,  and 
that  even  a  comparative!}"  slight  breeze  will  keep  them  from  upper 
stories  in  houses.  He,  therefore,  doubted  the  wide  distribution  of 
mosquitoes  by  high  winds.  Dr.  H.  T.  ^ernald  stated  that  at  Cold 
Spring  Harbor,  Long  Island,  with  a  north  breeze  there  are  no  mos- 
quitoes. With  a  south  breeze,  on  the  other  hand,  they  are  often  very 
troublesome,  especially  after  a  prolonged  gentle  wind  of  five  or  more 
hours'  duration.  There  are  no  pools  in  the  center  of  the  island,  and 
the  mosquitoes  are  supposed  to  have  been  carried  from  the  south  shore, 
a  distance  of  some  15  miles.  This  question  became  a  very  practical 
one  to  the  members  of  the  Richmond  County  Country  Club  on  Staten 
Island,  in  their  operations  against  the  breeding  places  of  mosquitoes 
on  the  island,  since,  if  a  new  supply  could  be  carried  over  hy  the 
winds  from  the  New  Jersey  coast  near  by,  a  large  portion  of  their 


14 

labor  would  be  wasted.  Mr.  ^\'.  ( '.  Korr,  the orij^iiiator  of  the  mos- 
quito work  at  that  placo.  and  an  cxcclhMit  ohscM'vcr.  is  dcc-idodly  of 
the  opinion   that   uioscjuitocs  aro  not  })routrht  over  from  New  Jersey. 

Ahnost  cNcrvoin'  must  liave  noticed  the  hal)it  of  mos(|uitoes  of 
elin»rintr  to  luanches  of  trees  ajid  j^i-jisses  durinir  a  hii^-h  wind,  swarni- 
in»r  out  in  tliLdit  as  the  wind  subsides.  ])ut  tliere  must  he  instances 
when  they  aic  LTcatly  aided  in  spreadinj^  by  such  gentle  winds  as 
those  mentioned  a))ove  by  Dr.  Fernald. 

In  this  connection  an  o})servation  made  Ijv  Mr.  \i.  M.  Keese  in 
Baltimore  is  siifniticant.  He  found  that  by  ti-eatinjr  the  privy  vault 
in  his  l>ackyai(l  with  kerosene,  the  su])})ly  of  moscjuitoes  to  the  house 
was  LTeatly  re(hiced.  althou<jjh  there  were  many  otlier  brecdinjr  places 
ordy  a  litth'  farther  removed. 

Another  siifnificant  instance  was  mentioned  )>y  Prof.  H«M*bert 
()s))orn  at  th(^  Boston  meeting  of  the  Association  of  Economic  Ento- 
mologists. He  said  that  in  dry  seasons  the  small  pools  w  ithin  a  quar- 
tei-  to  a  half  a  mile  fi'om  the  college  })uildings  at  Ames,  Iowa,  dry  up 
and  tlie  mosquitoes  disappear,  in  spite  of  the  fact  that  within  about  a 
mile  there  are  large  pools  which  never  lu'come  dry. 

On  this  point  Mrs.  (\  1^.  Aaron  writes  very  sensibly  as  follows 
(Dragon  Flies  7'.s'.  Mostpiitoes — The  Lam))orn  Essays,  Aj^ph^ton  &  Co., 
1.S90.  pp.  8.5-86): 

Tlu'  inigratiun  of  mosquitoes  h'dfi  ])een  tlie  source  of  imuli  luisiipurehengioii  (m  the 
])art  of  the  i>ul)lir.  The  idea  jirevak'nt  at  <mr  seasi(U'  resorts  that  a  hind  breeze  ]»rinp< 
the  swarms  of  mos(}uitoes  fmm  far  inland  is  based  on  the  sui»positioii  that  it  is  capable 
of  l<)nj;-siistaine(l  flijrht  and  a  certain  amount  of  hattHn*;a<rainst  the  win<l.  This  is  an 
error.  Mos<piitoes  are  frail  of  wing;  alijzht  puff  of  breath  will  ilbL-^trate  this  by  hurling 
the  helpless  creature  away,  and  it  will  not  venture  on  the  wing  again  for  8ome  time  after 
finding  a  safe  harbor.  The  prevalence  of  niosquitoe.s  during  a  land  ])reeze  is  easily 
explained.  It  is  usually  only  during  the  lulls  in  the  wind  at  such  times  that  Culex  can 
fly.  Generally  on  ourcoast  a  sea  breeze  means  astiff  breeze,  and  during  the.seeven  the 
Odonata,  and  often  the  ro])ust  and  ventursome  Tabanid;e,  will  be  f(»un(l  hovering  on 
the  leeward  side  of  the  houses,  sand  dunes,  and  thick  foliage.  In  the  meadows  south 
of  Atlantic  City,  N.  J.,  large  swarms  of  Culex  are  sheltered  in  the  dense  gra.<s  or 
wind-battered  tree  tops  on  the  off  side  of  the  sand  dunes.  Here,  in  common  with  all 
localities  so  exposed  to  searching  w  ind,  the  trees  and  hirge  bushes  are  much  stunted 
in  growth  and  battered  down  to  ^  flat  top  and  common  level  by  the  wind.  In  these 
matted  branches,  dense  with  the  close-clustered  foliage,  the  mos(]uitoes  may  be  dis- 
covered in  such  numbers  as  to  bring  despair  to  the  heart  of  the  student  who  is  plot- 
ting their  final  extermination.  While  the  strong  ])reezes  la.«t  Culex  will  stick  close 
t4)  the.>^'  friendly  shelters,  though  a  clustiT  of  houses  may  be  but  a  few  rods  off,  filUnl 
with  unsusix'cting  mortals  who  imagine  their  tormentors  :\rc  far  inland  over  the  salt 
mea<lows.  But  if  the  wind  dies  down,  as  it  usually  does  when  veering,  out  come 
swarms  upon  swarms  of  the  females  intent  upon  satisfying  their  depraved  taste  for 
blood.  This  explains  why  they  appear  on  the  field  of  action  almost  immediately 
after  the  cessiition  in  the  strong  breeze;  on  the  supposition  that  they  were  blown  far 
inland,  this  sudden  reappearance  would  l)e  unaccountable. 

Can^uHjc  of  ijiosfjuitoes  hy  ranimty  traim. — The  State  of  New^  Jersey 
has  an  unfortunate  reputation  in  connection  with  mosquitoes.     While 


15 

it  is  uiKl()ul)t(Hlly  true  that  inosciuitocs  an*  Ncrv  abimdaiit  in  most  |)ai-ts 
of  tho  State,  tliat  fact  doos  not  iiicaii  to  the  w  i-itrr  tliat  in  the  (greater 
part  of  the  State  there  are  any  more  hreedino-  spaces  or  that  moscpd- 
toes  are  an}^  more  prolilie  within  the  State  borders  thjm  elsewhere. 
It  does,  however,  seem  to  him  that  ther(^  is  constant  carriaj^-e  irdand 
from  the  marshy  seacoast  of  ver}'  many  mosquitoes,  but  ])y  this  \\v. 
does  not  int(Mid  to  convey  the  idea  that  they  are  carried  by  wind  or 
that  they  tly  to  any  great  distance  inhmd.  There  arc  other  means  of 
conveyance,  and  of  these  railway  trains  seem  to  be  very  important. 
All  through  the  summer  evenings  many  trains  are  started  inland  from 
Weehawken,  Hoboken,  Jersey  City,  South  Amboy,  Long  Branch, 
Atlantic  City,  Ocean  City,  and  Cape  May,  N.  ,].  Many  of  the  cars,  as 
the  writer  knows  from  experience,  contain  mosquitoes  by  the  hun- 
dreds. In  this  way  unlimited  quantities  of  mosquitoes  are  carried 
unlimited  distances,  and,  emerging  from  the  cars,  will  start  to  breed 
even  in  localities  where  mosquitoes  are  ordinarily  rare,  or  would  be 
rare  under  ordinary  conditions.  In  this  wa}^  even  mountain  resorts 
will  get  their  supply  of  lowland  mosquitoes,  and  with  the  improve- 
ment of  railway  service  and  the  increase  in  number  of  through  cars 
the  danger  is  constantly  increasing.  The  writer  knows  of  one  instance 
in  the  Catskill  Mountains  in  New  York  where  the  infestation  of  a  pre- 
viousl}^  uninfested  place  (;ould  have  been  brought  about  in  no  other 
Avay.  Through  parlor  and  through  baggage  cars  now  run  from  Jersey 
City  and  Weehawken  into  the  heart  of  the  Catskills  and  through  trains 
from  Boston  into  the  White  Mountains. 

In  the  same  way  through  cars  run  from  Baltimore  into  the  Blue 
Ridge,  and  thus  a  constant  source  of  supply  may  be,  and  undoubtedly 
is,  kept  up. 

How  long  can  the  larvoi  live  out  of  water? -^Kt  the  meeting  of  the 
Association  of  Economic  Entomologists  above  referred  to.  Dr.  Smith 
asked  if  it  were  possible  for  mosquitoes  to  breed  in  mud,  and  sug- 
gested that  there  was  no  reason  to  believe  that  the  actual  presence  of 
water  was  necessary  for  all  mosquito  species.  The  writer  has  seen  a 
statement  from  some  Californian,  which  he  is  unable  to  place  at  the 
present  time,  to  the  effect  that  there  is  a  prevalent  belief  in  some  parts 
of  the  United  States  that  when  a  surface  pool  dries  up  half -grown 
larvae  may  exist  in  the  drying  mud  for  some  time,  reviving  with  a 
fresh  rain.  Mr.  C.  x\.  Sperry,  of  Chicago,  wrote  us  early  in  1899 
and  advanced  the  same  theory.  He  said  that  experiments  made  in 
small  vessels  had  always  been  ver}"  unsatisfactory  to  him,  and  that  he 
abandoned  that  method  and  sought  the  natural  breeding  places  for 
investigation  and  experiment.  Earl}'  in  July  he  found  a  wet-weather 
pond  with  mosquito  larvae  in  it,  the  pond  being  nearly  dry.  In  a  few 
days  the  water  was  all  gone.  He  examined  closel}^  and  discovered  no 
dead  larvae.     In  about   a  week  it  rained,  and   as  soon  as  the  rain 


>t(»|i|M(|  lie  went  to  llir  i)l:u»'  and  found  tlh'  mosquito  lar\a':iil  throuji^h 
tlu"  watrr  as  li\rly  us  cvtT.  and  they  iK'j^jin  to  issiio-  jis  adults  about  :i 
\v<M'k  l'i-om  that  tiiuc  Aj^siin  he  discoNc^n'd  ji  place  whciv.  the  water 
had  ncaily  diicd  up.  and  hundreds  of  inoscpiito  hir\ii'  were  seen  }»y 
hiiii  on  the  \v««t  »^round.  Three  days  hit<'r  it  raiiiod,  and  ho  found  the 
laiNJi'  in  the  watei'us  Ii\<dy  as  e\-er.  In  the  same  way  Mr.  Benjamin 
S.  I^l^<•hall.  of  Newlield.  N.  d..  has  communieated  to  us  o})servations 
of  iii>^  own  whi<h  indicate  t<>  tiiin  a  possibility  that  mosciuitoes  umy 
lueed  in  iiiass  o|-  iuoi<t  eailh. 

lv\p«'i-iments  made  at  lhi>  ollice  on  a  small  scale  in  j^hiss  vessels 
lia\e  >hown  that  the  lai\a'  <d'  ( "ulex  will  exist  for  some  little  time  in 
wet  nmd,  atui  s<»me  of  them  will  succi'ssfully  tiansform  after  water 
ha>  heen  added.  In  no  case,  however,  were  we  ahle  to  revive  larva* 
in  mu<l  fi-om  which  the  water  had  h<'en  drawn  off  for  more  than  forty- 
eieht  hours,  and  aftei-  twenty-four  houis  ordy  a  small  proportion  of 
the  lai"\  a'  rexived.  An  interest  iii}^'  pool  has  heen  under  ohservation 
(hiririL:  lhe])re>ent  month.  The  pool  containinl  a  surface  area  of  about 
L'l  ><|uai-e  f(M't.  and  was  fed  entii'tdy  ])y  rain  water  and  surface  drain- 
ai:'e.  reaching- a  depth  when  full  of  about  1  foot.  All  through  the  sum- 
mer tliis  ])o()l  is  w(dl  st()cke(l  with  mos(juito  lar\ie.  After  a  somewhat 
Ioul:'  <lrouL:ht  tlie  watei*  was  observed  on  ffuly  IS  to  have  eva})orat<Hl 
almost  entirely,  a  small  puddle  in  the  center  of  the  cavity,  containing 
oidy  .")  or  4  cubic  inches  of  water,  remaining-.  It  was  dark  in  color, 
owinji'  to  the  drainage  from  a  manure  pile  near  by.  and  to  the  casual 
o})se!M'r  showed  no  signs  of  life.  The  water  in  this  little  puddle  was 
vvvy  shallow.  On  di])pin<^  in  a  c()tlee  strainer,  however,  it  was  found 
to  be  literally  massed  with  nearly  full-orown  mosquito  larv;v,  many 
hundrc'ds  of  which  htid  been  lirouoht  together  into  this  restricted 
place.  The  (IryinL!  (oiUimied  until  there  was  almost  no  water  left. 
()!i  the  nieht  of  the  '3H\\  came  a  heavy  rain,  followed  with  a  still 
hea\  i«'r  one  on  the  morning  of  the  '2'M.  On  the  :^.'>d  the  pool  was 
found  to  be  entirely  fidl  of  watei"  and  to  contain  its  usual  stock  of 
mos(piito  larva'. 

This  may  }>e  safely  said  to  indicate  the  usual  habit  of  mosquito 
lar\a'  in  e\aporating  ])ools.  As  the  water  gradually  recedes  toward 
the  deepest  portion  (d'  the  (wcavation,  the  lar\a'  reccMle  with  it,  con- 
centrating thems(dve<  at  the  deepcv^t  point,  i.  e..  at  the  ])oint  where 
the  moisture  remains  longest.  Knowing  as  we  do.  then,  that  even 
in  the  a)>sence  of  any  free  wat«M-  tlu^  laiva'  will  remain  ali\c  in  moist 
mud  for  from  twenty-four  to  forty-eight  hours,  it  is  e\  ident  that 
such  a  |)o(d  as  tin'  one  dcvscribed  gradually  drying  would  give  the 
api)earance  of  liaxing  l)een  pi-actically  .dried  u})  for  sonic  days  before 
the  last  <ul>ic  inch  of  free  water  has  entirely  disappt^ared.  The  con- 
centration of  many  lar\a'  at  this  point  in  the  manner  which  has  been 
descrilx'd  could  not  fail  to  give  rise  to  the  )>elief  that  mosipiito  larv^ai 


17 

will  exist  in  the  absence  of  free  water  for  a  iniieh  lon<^er  period  than 
is  reall}^  the  ease.  In  the  opinion  of  the  writer,  where  th(i  nuid  dries 
up  entirely  the  nioscpiito  larva*  are  necessarily  killed,  but  that  they 
may  exist  in  very  wet  nuid  for  a  longer  or  shorter  time  is  true. 

An  interesting  observation  ))earinj^-  upon  this  i)oint  has  ])een  made 
by  Dr.  St.  George  Gray,  of  Castries,  St.  Liuda,  Rritisli  AVest  Indies, 
and  reported  in  the  Journal  of  Tropieal  Medicine,  London,  May  15, 
1900.  He  says  that  on  Februarv  7,  1900,  he  examined  a  spot  where  he 
had  obtained  larvte  of  Anopheles  a  few  months  before.  The  pool  had. 
])cen  dry  for  three  weeks,  hardly  any  rain  having  fallen  during  that 
time.  The  surface  of  the  mud  at  the  bottom  was  cracked  and  dry, 
although  soft  enough  under  the  crust.  He  put  the  mud  into  a  clean 
pickle  bottle  and  put  about  3  inches  of  filtered  water  over  it,  but  there 
was  no  result.  He  also  took  some  grass  from  the  sides  of  the  pool  and 
put  that  grass  into  another  pickle  bottle,  adding  3  inches  of  filtered 
water.  On  the  following  morning  he  found  a  few  minute  larvae 
wriggling  about  in  this  bottle.  These  rapidly  grew  in  size,  and  he 
soon  had  a  half  dozen  healthy  looking  larvae  in  his  bottle.  On  the  21st, 
a  fortnight  after  he  had  taken  the  grass  from  the  sides  of  the  pool,  he 
reared  the  imago  of  Culex  tceniatus.  From  this  observation  he  argues 
that  some  species  of  Culex,  at  any  rate,  do  not  always  lay  their  eggs 
on  the  surface  of  the  water,  but  where  they  will  be  washed  into  the 
pool  by  the  first  heavy  rain.  Other  similar  experiments  were  failures. 
This  record  is  a  very  interesting  one,  but,  like  all  isolated  observations, 
needs  verification.^  It  may  here  be  mentioned  that  Drs.  J.  W.  W. 
Stephens  and  S.  E,.  Christophers,  in  their  article  on  ''The  distribution 
of  Anopheles  in  Sierra  Leone,"  published  in  the  reports  of  the  malarial 
committee  to  the  Royal  Society  (London,  July  6,  1900),  stated  that 
they  w^ere  unable  to  hatch  the  eggs  of  Anopheles  after  desiccation  on 
blotting  paper  for  more  than  forty-eight  hours,  although  they  hatched 
after  twenty-four  and  forty-eight  hours'  drying,  respectively. 

The  nuniber  of  species  of  mosquitoes. — As  regards  the  different  kinds 
of  mosquitoes,  about  250  species  are  known,  of  which  only  about  30 
have  been  found  in  the  United  States.  These  are  divided  into  5  differ- 
ent genera,  each  of  which  will  receive  consideration  in  the  following 
pages.  Of  the  malarial  genus  Anopheles,  Mr.  F.  V.  Theobald  writes 
us  there  are  27  species  in  the  British  Museum  collection. 

MOSQUITOES   AND   MALARIA. 

This  is  not  the  place  to  discuss  at  length  the  history  of  the  discover- 
ies which  have  brought  about  the  very  perfect  proof  that  mosquitoes 
may  and  do  transfer  the  malaria  germ  from  a  malaria  patient  and 

^Dr.  Walter  Reed,  U.  S.  A.,  tells  me  that  Dr.  Lazear  has  just  made  a  similar 
observation  in  Cuba. 

3949^—2 


18 

deposit  ii  ill  tlir  hlood  ot  a  hcaltliy  i)er.son.  Those  interested  are 
li't'ciiM'd  lo  llir  :i(liiiii-:i})l«»  })aj)<'r  entitled  ''On  the  role  of  insects, 
Aiachnids  and  M\  liapods,  as  i-arriers  in  the  spread  of  Imeterial  and 
j)arasitie  dis<»ases  <»!'  man  and  animals;  a  critieal  and  historical  study," 
})y  (ie()rw-(>  II.  Xuttall,  M.  D.,  Ph.  D..  puldished  in  Volume  VIII  (►f 
the  Johns  Hopkins  Hos|)ital  Ue})oits.  and  to  latei-  American  sununaries, 
amonjr  whi<li  may  Ix-  mentioned  that  hy  I)|-.  W.  N.  Berkeley  in  the 
New  York  Medical  Record  for  l)ecemi>er  i>:),  1S1»0,  ])y  Dr.  Alhert 
Woldert  in  the  Jouifial  of  the  American  Medical  Association  for  Fid)- 
ruary  1<».  I'.mmi.'  and  l»y  Dr.  William  Hritt  lUirns  in  the  Memphis  Medi- 
cal Monthly  for  March.  \\H){).  One  of  the  most  thorou*,^!  of  the  recent 
reviews  will  )>e  found  in  Xaturt*  for  Mai'ch  '2\K  l'.*0(»,  paj^es  522-5:^7, 
entitled  ''Malaiia  and  moscpiitoes,"  a  lecture  delivered  at  the  Royal 
Institution  of  (Jreat  Britain  on  March  '2,  ])y  Maj.  Ronald  Ross,  D.  P.  H., 
M.  R.  ('.  S..  lecturer  in  tropical  medicme,  University  Collei^e,  Liver- 
pool, himsidf  OIK*  of  the  Avorkers  whose  results  contributed  most 
materially  to  the  establishment  of  detinite  proof.  Another  recent 
account  will  be  found  in  the  Popular  Science  Monthly  for  ,Iuly,  lUOO, 
l)y  Dr.  Patrick  Manson,  entitled  *' Malaria  and  the  malarial  parasite." 
It  should  be  stated  here,  howeviM'.  that  only  the  mos<juitoes  of  the 
genus  Anopheles  have  ])een  found  to  contain  the  human  blood  para- 
sites, alth()Utj;h  it  (lo(\^  not  appear  from  the  published  accounts  which 
have  met  the  writer's  eye  that  any  other  genera  than  Anopheles  and 
Culex  have  been  studied  in  this  connection. 

The  Italian  observers  have  found  that  all  three  species  of  the  human 
HaMuamoebida^  are  cultivable  in  Afioj)/te/fS  cJaru/rr  and  not  only  in 
this  })ut  in  other  Italian  species  of  Anopheles,  while  the}^  together 
with  Ross  and  other  observers,  have  failed  to  cultivate  the  parasites 
in  ( 'ulex.  The  same  fact  is  upheld  by  the  extended  observations  made 
in  AVest  Africa  and  in  this  country  so  far  as  observations  have  been 
made  as  yet.  The  writer,  however,  wishes  to  emphasize  the  point 
which  he  made  before  the  Ameiican  Medical  Association  on  June  6, 
IJHiO.  that  American  physicians,  (vspecially  those  in  the  Southern  States, 
should  not  d(day  the  invv'stigation  of  the  very  large  moscpiitoes  of  the 
genus  Psor()i)hora  and  Megarhinus  f.  om  the  malarial  standpoint.  Both 
of  these  genera  ha\'e  been  ligured  and  descrilied  in  succeeding  pages. 

SYNOPTIC   TABLES   OF   THE    NORTH    AMERICAN    MOSQUITOES. 

In  order  to  iMiable  the  ready  determination  of  our  different  mos- 
(juitoes  the  writer  ])ublished  in  Circular -iO,  second  series,  of  this  office, 
in  Fehruar}'  of  the  present  year,  a  series  of  tables,  drawn  up  at  his 
request  by  Mr.  D.  W.  Ccxjuillett,  of  the  office  force,  comprising  (1)  a 

^  Dr.  Woldert's  article  contains  a  good  account  of  the  internal  anatomy  of  mosqui- 
toes and  describes  his  methods  of  dissection. 


10 

S3'nopsis  of  the  Hvo  j4"iM'*''''*  iiiidci-  w  liicli  Ihc  I(»nu  ))«';ik(Ml.  hlocxl-suck 
iiig  spei'ios  known  to  occiii-  in  Noilli  America  wcic  dixidcd;  (2)  ji 
synoptic  considci-ation  of  the  sp(H'ics  of  (he  ncniis  Cidcx.  divided  into 
(a)  ta])le  of  the  iHM'oiiiii/cd  species,  s])C(inieiis  of  which  occur  in  the 
National  Miiseuni  coUection,  and  (/>)  an  account  of  the  unrecognized 
species,  whicli  are  known  oidy  from  tlie  literature;  {?>)  a  synoptic  con- 
sideration of  tlu>  s])ecies  of  the  o-enus  Anopheles.  (li\ided  into  (//) 
recoo-nized  forms,  and  (/»)  unrcH'ooni/ed  forms;  (4)  a  ))rief  description 
of  the  only  valid  known  species  of  the  o(muis  Psorophora;  (;">)  a  synop- 
tic table  of  the  three  known  species  of  the  genus  Megarhinus;  and  (()) 
a  svnoptic  consideration  of  the  two  known  species  of  the  genus  Aedes. 
Mr.  Coquillett's  tables  are  here  reprinted  with  slight  changes: 

I. — Generic  Synotsis. 

The  following  table  contains  all  tlie  genera  of  the  long-beake<l  mosquitoes  known 
to  occur  in  North  America.  The  males  are  readily  recognized  ])y  the  antennte  being 
densely  covered  with  long  hairs;  in  the  females  the  hairs  of  the  antenna?  are  short 
and  very  sparse: 

1.  Palpi  in  the  male  at  least  nearly  as  long  as  the  proboscis;  in  the  female  less  than 

one-half  as  long : 2. 

Palpi  in  both  sexes  at  least  almost  as  long  as  the  proboscis Anopheles. 

Palpi  in  both  sexes  less  than  one  half  as  long  as  the  proboscis Aedes. 

2.  Proboscis  straight  or  nearly  so,  colors  of  body  brown  and  yellowish 3. 

Proboscis  strongly  curving  downward  toward  the  tip,  colors  bluish  or  greenish. 

.Megarhinus. 

3.  Legs  bearing  many  nearly  erect  scales Psorophora. 

Legs  destitute  of  such  scales Culex. 

JI.— (texcs  ('ulex. 

(«)    KECOGXiZEI)    SPECIES. 

Malex. 

1.  Front  tarsal  claws  bearing  a  distinct  tooth  ii(>ar  the  middle  of  the  underside  of 

each 3. 

Front  tarsal  claws  bearing  two  teeth  on  the  underside  of  one  claw,  and  one  on 
underside  of  the  other,  proboscis  destitute  of  a  whitish  band  near  the  mid- 
dle   2. 

Front  tarsal  claws  with  one  tooth  on  underside  of  one  of  the  claws,  none  on  the 
other,  bases  of  tarsal  joints  white,  proboscis  destitute  of  a  whitish  band  near 
the  middle fasciatus  Fabr. 

2.  Tarsi  distinctly  white  at  bases  of  the  joints exritans  Walk. 

Tarsi  not  white  at  bases  of  the  joints (Wisobrinns  Desv. 

3.  Proboscis  destitute  of  a  whitish  ring  near  the  middle 4. 

Proboscis  with  such  a  ring,  ends  of  tarsal  joints  white tarsalis  Coq. 

4.  Bases  of  tarsal  joints  not  white 5. 

Bases  of  tarsal  joints  white stimulans  Walk. 

5.  Petiole  of  submarginal  cell  less  than  one-third  of  the  length  of  that  cell. 

pungens  Wied. 
Petiole  of  submarginal  cell  at  least  one-half  of  the  length  of  that  cell. 

impiger  Walk. 
Females. 

1.  Front  tarsal  claws  bearing  a  distinct  tooth  near  middle  of  iindersideof  each..  2. 
Front  tarsal  claws  destitute  of  teeth , 7. 


20 

2.   l*n>lM)(*cis  (IcHtimto  «»f  a  white  riii>;  lu-ar  the  middle 3. 

Pruho.'ii-iH  iiiarketl  with  .^ach  a  rinj:,  ha.<<'S  of  tarsal  joints  white. 

l:niiorln/nehits  Wied. 

'A.  liiUH^H  of  tarsal  joints  distinctly  white 4. 

Iias«'s  of  tarsal  joints  never  white 5. 

A.    Mrsonotmn  inarkrd  with  fonr  stripes  of  silvery  scales fcusciatua  Fabr. 

Mesonotuni  (h'stitiite  of  such  strijK's: 

Kiftii  joint  of  hind  tarsi  white ixnlfffus  Wit'tl. 

Fifth  joint,  except  its  extreme  base,  dark  brown ftimnltniA  Walk. 

T).    I^ist  two  joints  of  hind  tarsi  never  white (i. 

l^ist  two  joints  of  hind  tarsi  snow  white pontiaiiuH  Wied. 

(».    Alwlt.nn'n  marked  witii  a  cross  l)and  of  whitish  scales  at  l^ase  of  each  segment. 

un}n(j(r  Walk. 
AlMlomcn  nev»'r  marke<l  in  this  manner,  but  with  a  cluster  of  whitish  scules  at 

front  anodes  of  some  of  the  sej^Miients irixcnatris  Say. 

7.    Tidboscis  marked  with  a  distinct  whitish  rin^  near  the  middle,  tai-si  white  at 

sutures  of  the  joints 8. 

Proboscis  <lestitute  of  a  whitish  rin^  near  the  nnddle 9. 

S.    Tarsal  joints  white  at  bases  only peiiurhdns  Walk.' 

Tarsal  joints  white  at  both  ends tarmllx  Coq. 

\K    Tarsi  white  at  bases  of  joint« 10. 

Tarsi  never  white  at  bases  of  the  joints 12. 

10.  Mesonotum  never  marked  with  stripes  (»f  silvery  scales 11. 

Mesonotum  marke<l  with  four  striju's  of   silvery  scales,  first  tarsal  joint  never 

marked  with  a  whitish  rin«;  near  the  middle sifjui/er  Coq. 

1 1.  First  tarsal  joint  niarke<l  with  a  whitish  rin^'  near  middle  of  each. 

rxcTuriariH  W^alk. 

Fii-st  tarsal  joint  destitute  of  such  a  rin^ rrriUma  Walk. 

IL*.    Petiole  of  submar^inal  cell  less  than  one-third  of  the  len<:tli  of  that  cell. 

jiungenx  Wie<l. 
Petiole  of  submarginal  cell  at  least  almost  one-half  of  the  length  of  that  cell. 

consobrinus  Desv. 

{}))     rNKKCO(iNlZKI)    Sl'KClHX. 

<in)iiil(tfns  Schrank.  This  Furopean  species  was  credited  to  our  fauna  by  Osten 
Sacken.  The  description  a<rrees  fairly  wi'll  with  spi'cimens  which  I  have  identiHerl 
•Afi  rrcif  a  IIS,  Walker,  e.xcei)t  that  in  the  latter  there  is  no  white  ring  on  the  femora 
toward  their  apices. 

hosrii  Desv.     Proba])ly  a  rnb])e<l  sjH'cimen  of  -jiiinfjnu. 

iii(jrijus  Zett.  Black,  the  legs  of  the  male  <lark  yellow,  hairs  of  ])leura  of  female 
gray,  a  band  of  white  scales  at  base  of  each  segment  of  her  abdomen. 

ndiiiliiH  Desv.  The  description  was  api)arently  founded  on  a  rubbed  specimen  of 
P.siiiojilioni  ciliato. 

(i'Kidrnis  V.  d.  Wulp.     Is  probably  a  somewhat  injured  example  of  mtifdthriuns. 

iiiridnis  Thomson.     Is  evidently  a  synonym  of  hnpigir  Walker. 

hiffofi  Bellanli.  Accordiui:  to  ti:e  figure  and  descri])tion,  the  bands  of  black  scalofs 
are  at  the  /^a.sv.sof  the  abdominal  segments;  in  the  recognized  sp(»cies  thesi'  ])an<ls  are 
always  at  the  apices  of  the  segments.  In  other  resjjccts  this  species  nmst  greatly 
resemble  jniiif/riix. 

ciihnisls  Bigot.     Apparently  founded  on  a  l)adly  rublx?<l  six'cimen  of  pnngens. 

fi'dUr  Desv.  This  name  was  jiroposed  for  the  ('nli\r  fiiifcldlu.s  of  Wiedemann,  under 
the  impression  that  this  is  not  the  same  s|)ecies  as  the  one  describe*!  by  Fabriiius 
un«ler  the  same  nanie.  It  seems  quite  certain,  however,  that  the  word  "proboscis" 
in  Kabricius'  <lescription  was  simply  a  lapsus  for  "i)alpi,"  and  with  this  emendation 
the  two  descriptions  agree  very  well. 

incxirtimi  Bellardi.      Is  evidently  a  synonym  of  postimtns. 

prororniis  Walker.  Is  probably  a  synonym  of  stiiiiKhuis.  In  some  specimens  of 
this  speciis  the  light  color  at  the  bases*  of  tlie  tarsal  joints  is  very  indistinct. 

Urritunx  Walker.     Is  apparently  a  syuonyui  of  punyciis. 

'Mr.  F.  V.  Theobald,  after  ptudying  Walker's  type  of  perlurbans,  writes  us  that  it 
has  toothed  claws  in  the  female. 


Our  rooop:nizo(l  sju'cic^- 
svnonviMS  iiidciitiMl: 


>f  ( 'ulcx  anil  t  lu'ir  sviiomn 


l)f  list('(|  :is  I'ollows,  til 


coiisohriii  Ufi  I  )esv . 

?  arini(lim(inus    \.   d.    A\'iili>   (Ano- 
pheles). 

impdtlciis  Walker. 

inonuttii.^  Williston. 

])in(jiiis  Walker. 

pnnrtor  Kirhy. 

?  tt'stdcnis  V.  (I.  AN'ulp. 
e.rcitdiu  Walker. 

?    (iiniit/dtiis     Osteii     Sacken      {nee 
'Mei.treu,  etc.). 
exmtrkdis  Walker. 
J'mriddts  Vnhv. 

f rater  Desv. 

iiiffstjiiito  Desv, 
iaeniatns  Wied. 
impiyer  Walker. 

implarahlllx  Walker. 

incident  Thomson. 

?  quinquefasciatus  Say. 


jxrliirlxniti  Walker. 
j)(},slic(ihis  Wied. 

?  iiiexiadiKs  l>ellardi. 

Ill  1 1  sit- lis  Say. 
piiiK/i'iis  Wied. 

?  hoscil  Desv. 

?  riihenxis  Jii<j;()t. 

?  farilans  Walker. 
ngnifer  Coqiiillett. 
stiimddiiH  Walker. 

?  prorocdiis  Walker. 
iaenior/it/iicliiis  \\'ied. 

ilaiiniosns  Say. 

ml/iciUm.H  AV'alker. 
tarmlis  Coquillett. 
Inseriatus  Say. 


III. — Genus  Anopheles. 

(a)    KECO(iNIZEI)    SPECIES. 

With  a  yellowish  white  spot  near  three-fourths  of  the  length  of  the  front  margin 
of  the  wing;  scales  of  last  vein  white,  those  at  each  end  black,  pundipennu  Say. 

Without  such  a  spot 2. 

Scales  of  last  vein  wholly  black,  palpi  wholly  black quadrimaculatus  Say. 

Scales  of  last  vein  white,  marked  with  three  black  spots,  palpi  marked  with  while 
at  bases  of  last  four  joints crucians  AVied. 

(h)     TTNRECOGNIZED    SPECIES. 


The  following  species  which  have  been  credited  to  our  country  have  not  been 
recognized  with  certainty;  some  of  them  probably  do  not  belong  to  the  present 
genus,  while  a  few  were  evidently  founded  on  badly  rul)bed  specimens  in  which  the 
distinctive  characters  were  therefore  wanting: 

annulimamis  v.  d.  Wulp.  I  strongly  suspect  that  this  does  not  belong  to  the  present 
genus;  the  description  applies  fairly  well  to  the  male  of  Chdex  consohr'mns  Desv. 

ferruglnoms  AVied.  This  author  proposes  this  name  for  the  species  previously 
described  by  Say  under  the  name  of  Culex  quinquefasciatus,  but  the  descripti(^n  which 
he  gives  differs  so  decidedly  from  the  one  published  by  Say  as  to  give  the  impression 
that  it  is  founded  on  a  different  species.  I  strongly  suspect  that  the  type  of  ferni- 
ginosusis  a  rubbed  example  oi  Anopheles  crucians,  which  was  described  from  the  same 
locality.  Say's  description  of  his  Culex  quinquefasciatus  agrees  very  well  with  the 
species  which  I  have  identified  as  Ctdex  imjnger  Walker. 

macidipennis  Meigen.  I  strongly  suspect  that  this  European  form  is  identical  with 
our  Anopheles  quadrimaculatns  Say,  but  this  point  can  not  be  settled  definitely  at 
present,  owing  to  the  lack  of  any  iEuroi)ean  specimens  for  comparison  with  ours. 

nigripes  Staeger.  This  European  species  should  be  readily  re{!Ognized  by  its 
unspotted  wings. 

a.lbimanus  Wied.  Differs  from  our  other  species  by  the  snow-white  apices  of  the 
tarsi. 

Anopheles  pictus  Loew  is  evidently  a  synonym  of  A.  crucians  AVied. 

Our  recognized  species  of  Anopheles  and  their  synonyms  may  therefore  be  listed 
as  follows,  the  synonyms  indented: 

crucians  AVied.  -  pundipennis  Say. 

pictus  Loew.  hiemalis  Fitch. 

1  ferruginosus  AVied.  quadrimaculatus  Say. 

?  maculipennis  Meigen. 


I  \  .--«  ii:\l  V     I'-.iiioIMlORA. 

<  Mil  -iiiLiK  -jMi  M  ~  1-  ...  a  yrllowish  color,  usually  varicil  with  brown,  tlie  l>a>«eH  ot 
tlu'  tarsiil  juiiitM  white.  It  is  coiisidfiiihly  larger  than  any  uf  uur  other  s|)eeie«  of 
yellowish  or  hrowii  iintsi|iiitoeK: 

filitittm  Fahr. 

fimlti'iuiis  Walker. 
till titxt IIS  NN'ieW. 

?  iilbitln,^  Pesv  . 

y. (lENlS    "Mi:<iAHMINrs. 

(  Mil  three  ^ju'iies  ai»'  aiiioii;j  the  largest  in  this  family,  and  are  imt  kn(»wii  to  ueeiir 
north  ol  the  histriet  of  ( 'oliiniitia.      They  may  he  separated  as  fulhtus: 

All  tarsi  marked  with  white ruiilius  Coq. 

I  lind  tar.-i  alone  marki-d  w  ith  wliite p</ilorirewtiif  Roeder. 

None  (if  the  tarsi  marked  with  whitt    .  Im iiioi'rhoi(]<ifij<  F'dltr. 

\'l. <  iK.M  s    AkI)1>. 

*»iii  iNM.  ^|H^l^-  o.  .iiiM.i.u  the  smallest  of  our  mosquitoes,  an<l  havt^  a  jtale 
hmwuish  ground  color.     They  may  Ik-  «listinguished  as  follows: 

Thorax  marked  with  a  njedian  violet  hlue  striiu' sapphirinuit  O.  S. 

Thorax  destitute  of  such  a  strij.e fnxrus  O.  S. 

THI.    1U(U,<»(;^     OF    CILK.X.    WITH     liK.MAKKS    I  fON    S<  )M  K    <)l"    THK    SPKCIES. 

h  is  toh'iahly  (('i-tiiiii  th:it  the  life  found  of  nil  of  the  species  of  the 
o-eiiii>  (iih'x  is  juactirailv  the  sumo.  They  will  differ  more  or  less  in 
the  cliaraeter  of  tlie  water  in  wJiich  they  ])referahly  ]>reed.  and  dift'er- 
ino-  in  this  re.^pect.  they  will  ditfer  also  in  some  degree  in  their  pre- 
ferred food,  which  consists  of  all  sorts  of  aciiiatic  mieTo-orgaiiisms. 
Down  to  the  tiin«'  when  the  writer  puhlished  his  account  of  Cultx 
jHimjtus^  in  l^ulletin  No.  4.  New  Series,  of  this  otfic(»,  there  was  not 
in  any  puhlished  work  a  thoroughly  satisfactory  figure  of  a  well- 
determined  species  of  moscpiito  from  the  Unitx^d  States,  or  of  its 
earlier  stages.  The  statements  (juoted  in  the  text-hooks  and  maimals 
dated  })ack  in  general  to  the  time  of  Keaiunur- more  than  one  hun- 
dred and  fifty  years  ago.  Reaumur's  observations  were  made  in  the 
month  of  May  upon  a  species  {( 'hIcv jhjh^'hs)  which  does  not  occur  in 
North  America,  and  the  observations  were  all  made  at  Paris,  so  that 
statements  a-;  to  tlii'  duration  of  the  insect  in  any  stage  woidd  be 
incorrect  cNcn  for  the  same  sj)ecies  in  a  warmer  or  colder  locality. 
The  following  accoiuit of  the  life  history  of  Cdh.r  puiKjins  (tig.  1)  is 
(|iiot»'(l  from  the  writer's  bulletin  aboxe  cited: 

L'ifi  li'isinrij  i>f  ('i(/r.i'  j>uji(/rths.--V\\v  operation  of  i')i)f  laying  was 
not  obseiAM'd,  but  it  probably  tak(\s  place  in  the  very  early  morning 
lioiiis.  \\\v  eggs  are  laid  in  the  usual  boat-shaped  mass,  just  as  those 
of  r//A./'yy/y>//7/.v.  as  described  by  l^eaumur.  We  say  boat -shai^'d  mass, 
becaus*'  that  is  the  ordinary  expn^ssion.  As  a  matter  of  fact,  however, 
the  egg  masses  are  of  all  sorts  of  shapes.     The  most  common  one  is 


^ 


28 


tla'  ])()iiit(Hl  ellipse,  convex  Ix'Ionn  and  coiieuN ««  above,  all  llie  e«^*^*s  per- 
peiulieiilar,  in  <>  to  \'^  lono'itiulinal  rows,  with  iVoiii  IJ  or  1  to  4< )  eoo-.s  in 
a  row.  I'he  mnnherot'  eo-L;-s  in  each  l>alcli  \aries  i'l-oni  200  to  400.  As 
seen  from  ahoNC  tlie  eii'Ll'  mass  is  i4rav  hi'owii:  t'l'om  helow,  silverv 
Nvliite.  the  latter  appearanc«'  heiny'  due  (o  (hr  aii"  lilm.  It  seems 
im})ossil)le  to  wel  thes(»  coo-  masscvs.  'Phey  may  he  j)iishe(l  under 
water,  but  hob  up  ap})arently  as  dry  as  ever.  TIh^  ego-  mass  separates 
rathei-  reoularlv,  and  the  eo'sis  ar(^  not  stuck  tooether  very  firmlv. 
After  they  have  hatched  the  mass  ^\iil  disinteorato  in  a  few  days,  even 
in  perfectly  still  Avater. 

The  individual  ejiiis  are  o.T  mm.  in  lenoth  and  0.16mm.  in  diameter 
at  the  base.  They  are  slender,  broader  and  blunt  at  bottom,  slenderer 
and  somewhat  pointed  at  tip.     The  tip  is  always  dark  grayish  brown  in 


Fig.  1. — C'ulex  panyeas:  Egg  mass,  with  euglarged  eggs  at  left  and  young  larvae  below — enlarged 

(original) . 

color,  while  the  rest  of  the  egg  is  dirty  white.  Repeated  observations 
■show  that  the  eggs  hatch,  under  advantageous  conditions,  certainly 
as  soon  as  sixteen  hours.  Water  buckets  containing  no  Qgg  masses, 
placed  out  at  night,  were  found  to  contain  Qgg  masses  at  8  o'clock  in 
the  morning,  which,  as  above  stated,  were  probably  laid  in  the  early 
morning,  before  daylight.  These  eggs,  the  third  week  in  May,  began 
to  hatch  quite  regularly  at  2  o'clock  in  the  afternoon  of  the  same  da}^ 
on  Avarm  days.  In  cooler  weather  they  sometimes  remained  unhatched 
until  the  second  day.  If  we  apply  the  evidence  of  European  observers 
to  this  species,  the  period  of  the  ^gg  state  may  be  under  twelve  hours; 
but  there  is  a  possibilit}-  that  they  are  laid  earlier  in  the  night,  which 
accounts  for  the  fact  that  sixteen  hours  is  the  shortest  period  which  we 
can  definitely  mention. 


24 

Tlu'  hirvji'  issue  fioiii  tlir  undt'isich*  of  the  og^  mjissos.  siiid  are 
extreiiu'ly  ju-tivr  at  iMrth.  AVhcii  lirst  olhserved  it  is  oasy  to  fall  into 
an  error  n'trardinir  the  lent^th  of  time  which  they  can  remain  under 
water,  or  i-ather  without  coming  U>  i\w  surface  to  breathe,  since,  in 
strivinij;-  to  come  to  thi'  surface  for  air,  many  of  them  will  strike  the 
undei*sid*'  of  the  egg  mass  and  remain  there  for  many  minntes.  It  is 
altogetlier  likely,  however,  that  they  get  air  at  this  point  through  the 
ej^j^s  or  through  the  air  film  l>v  which  the  Oirir  niass  is  surrounded,  and 
that  they  are  as  readily  drowned  hy  contiruions  inmn'ision  as  are  the 
older  ones,  as  will  )>c  shown  latei-. 

One  of  th(^  first  peculiarities  whicii  stiikes  one  on  oriserving  these 
ncNsly-hatclird  l;ir\a'  under  thr  lens  is  tliat  tin-  tufts  of  filaments  which 
aie  conspicuous  at  th«'  mouth  arc  in  a)»so]utcly  <'onstaiit  \  i))ration.  This 
j)eculiarity.  and  the  wriggling  of  the  lar\a'  through  the  water,  and 


M   ' 

I 


' iikx piinycns:  Ilead  of  larva  from  helow  at  k'ft;  saiiu*  fnnn  a]M)\«.»  at  rifjht— greatly  enlarged 

(original"!. 

their  great  activity,  render  thcin  interesting  objects  of  study.  In  gen- 
eral the  larva',  passing  through  :4)j)arently  three  different  stages,  reach 
maturity  and  transform  to  pupa*  in  a  minimum  of  seven  days.  When 
nearly  full  grown,  their  movements  were  studied  with  more  care,  as 
they  were  casitM'  to  o])serve  than  when  newly  hatched.  At  this  time 
the  larva  remains  near  the  surface  of  the  water,  with  its  respiratory 
siphon  at  the  exact  surface  and  its  mouth  filaments  in  constant  vil)ra- 
tion,  directing  food  into  the  mouth  cavity.  Occasionally  thi^  larva 
descends  to  the  ))ottom,  l)ut,  though  repeatedly  timed,  a  healthy  indi- 
vidual was  ne\ cr  seen  to  remain  voluntarily  below  the  surface  more 
than  a  minut(\  Tn  ascending  it  comes  up  with  an  eti'ort,  with  a  series 
of  jeiks  and  wrigglings  with  its  tail.  It  descends  without  eti'ort,  Imt 
ascends  with  difficulty:  in  oth(M-  words,  its  specific  gravity  seems  to  Ije 
greater  than  liiat  of  tlu'  watei-.     As  soon,  however,  as  the  respiratory 


25 

siphon  vciU'lu^s  tho  siirfjico,  frcsli  air  flows  iiilo  its  trjichcu',  juul  the,  pliys- 
ical  prop(»rti(\s  of  tlio  so-calliul  surface  iiliii  of  the  Avatcr  assist  it  in 
inaintiiining  its  position. 

The  respiratory  tii))e  takes  its  origin  from  the  tip  of  the  eighth  ab- 
dominal seo-meiit,  and  the  very  larye  trachea*  can  ))e  seen  extending  to 
its  extremity,  Avhere  they  have  a  double  oritice.  The  nintli  segment  of 
th(»  abdomcMi  is  armed  at  the  tip  with  four  flaps  and  six  liaii's,  as  shown 
in  lig.  8.  These  flaps  ar(*  gill-liki^  in  appearance,  though  they  are  prol)- 
ably  simply  locomotory  in  function.  With  so  remarkably  dcn^elopedan 
apparatus  for  dii-(M't  air  breathing  there  is  no  necessity  for  gill  struct- 
ures. Haschke  *  and  Hurst'- consider  that  tin*  larva  breathes  both  b}^ 
the  anus  and  by  these  gill  flaps,  as  well  as  by  the  large  tracheae  which 
open  at  the  tip  of  the  respirator}^  tube.  Kaschke  considers  that  these 
tracheae  are  so  unnecessaril}^  large  that  they  possess  a  hydrostatic 
function.  The  writer  is  inclined  to  believe  that  the  gill  flaps  may  be 
functional  as  branchial  structures  in  the  young  larva,  but  that  they 
largely  lose  this  ofiice  in  later  life. 

After  seven  or  eight  da^-s,  at  a  minimum,  as  just  stated,  the  larva 
transforms  to  pupa.  The  pupa,  as  has  been  repeatedly  pointed  out 
with  other  species,  differs  most  pronouncedly  from  the  larva  in  the 
great  swelling  of  the  thoracic  segments.  In  this  stage  the  insect  is 
lighter  than  w'ater.  It  remains  motionless  at  the  surface,  and  when 
disturbed  does  not  sink  without  effort,  as  does  the  larva,  but  is  onl}^ 
able  to  descend  by  a  violent  muscular  action.  It  wriggles  and  swims 
as  actively  as  does  the  larva,  and  soon  reaches  the  bottom  of  the  jar 
or  breeding  place.  As  soon  as  it  ceases  to  exert  itself,  however,  it 
floats  gradually  up  to  the  surface  of  the  water  again.  The  fact,  how- 
ever, that  the  larva,  after  it  is  once  below^  the  surface  of  the  w^ater,  sinks 
rather  than  rises,  accounts  for  the  death  of  many  individuals.  If  they 
become  sick  or  weak,  or  for  any  reason  are  unable  to  exert  sufficient 
muscular  force  to  wriggle  to  the  surface  at  frequent  intervals,  they  will 
actually  drown,  and  the  writer  has  seen  many  of  them  die  in  this  v^ay. 
It  seems  almost  like  a  contradiction  in  terms  to  speak  of  an  aquatic 
insect  drowning,  but  this  is  a  frequent  cause  of  mortality  among  wrig- 
glers. This  fact  also  explains  the  efficacy  of  the  remedial  treatment 
w  hich  causes  the  surface  of  the  water  to  become  covered  with  a  film  of 
oil  of  any  kind.  Aside  from  the  actual  insecticide  effect  of  the  oil,  the 
larvae  drown  from  not  being  able  to  reach  the  air.  The  sti'ucture  of  the 
pupa  differs  in  no  material  respect  from  that  of  corresponding  stages 
of  European  species,  as  so  admirably  figured  and  described  by  the  older 
writers,  notably  Reaumur  and  Swammerdam^  and  needs  no  description 

^Raschke,  Die  Larve  von  Culex  nemorosus,  Berlin,  1887. 
2  Hurst,  the  Pupal  Stage  of  Culex,  Manchester,  1890. 

^Even  Bonanni,  in  1691,  gave  very  fair  figures  of  the  larva  and  pupa  of  a  European 
species.     Micrographia  Curiosa,  Rome,  MDCXCI,  Pars.  II,  Tab.  I. 


^>c, 


III   \  H-NN    <»l     llirraM     willi   wllirli    liic    ii^ui»>    ;i(  (« »iii)  >:iii  \  i  ii<;^    llii>    :illi 

lm\<'  Im'cii  draw  II.  Tln'  air  tuln's  mo  lontroi-  optn  at  llir  anal  end  of  the 
))o(lv,  hut  tlir<»iiiili  two  t!'iiiiip('t-sha}H'(l  sch'rit4's  on  tin*  thorax,  from 
wliiih  it  roiihs  that  tlu'  ])iipa  iM'inalns  uprjirht  at  thf  surfac*',  iiistciicl 
of  w  ith  the  ht  jul  (h»u  ii\\ar(l.  I'hrrc  is  a  \rr\  appariMil  oliject  in  this 
rr\ri-^al  mT  the  p(»^ition  of  the  Imkiv,  siiR't*.  tht'  adult  ins(»rt  issues  from 
th«'  thorax  and  immmI-  th«'  tloatiiiL''  >kin  to  sup])ort  it^tdf  whih' its  wings 
art'  <'Xpandiiitj-. 

In  LjriM'ral.  thr  adult  ins«M*ts  issu«'  from  the  pupM-   that  art'  two  days 


Fi«i.  :i. — Cult X  till iKjt lis:  Fiiil-giDwu  larva  at  Ifft,  |>u|ja  al  fIkIiI — cularKt'd  (itrig^inal). 

old.  This  iii\('s  what  is  ])rohai>ly  the  mininiuin  oiMU'ration  for  this 
species  as  t<ii  (hiys,  namely,  sixteen  to  twenty-four  hours  for  the  egg, 
seven  days  for  the  larva,  and  two  days  foi-  tiie  ])upa.  The  individuals 
emerging  on  the  lirst  day  were  invariably  males.  On  the  second  day 
the  great  majority  w  ere  males,  l>ut  there  were  also  a  few  females.  The 
]ir(^})onderan('«'  of  males  continued  to  hold  for  thriM^  days;  later  the 
females  wci-e  in  the  majority.  In  <-ontinement  the  maley  died  quickly; 
se\«ral  li\  cd  for  four  days.  l)ut  none  for  more  than  that  period.  The 
femalo.  however.  li\ed  for  a  much  longeitime.      Some  were  kept  alive 


I 


27 

without  food,  ill  :i  conliiuMl  spacc^  of  not  more  than  4  iiiclics  (h'cp  l)y  6 
across,  for  three  AV(M»ks.  lint  one  cii^*  mass  was  (l(»]){)sil('(l  in  conlinc- 
nuMit.  This  v,as(l('[)()sil(Ml  on  tiir  nioriiino-  of  June  )I0  hy  a  tVniaic  w  hich 
issued  from  the  pii[)a  flune  '21.  No  furtiier  ohser\atioiis  wen^  made 
upon  the  time  elapsino-  ])etween  the  emerocnee  of  th«^  fennde  and  the 
hiyinvj'  of  (he  (\Lt<:s,  hut  in  no  ease.  j)roha))ly.  does  it  exceed  a  lew  daNS. 
The  h'niith  of  time  which  (da|)ses  for  a  i^"enei"ation,  wliich  we  have 
just  mentioiuHl,  is  almost  inch^tinitely  enlaro-ed  if  the  weather  he  cool. 
As  a  matter  of  fact,  a  h)no-  .spell  of  cool  weather  followed  the  issuing 


Fig.  4. — Culex pungena :  Female  above,  male  below — enlarged  (original). 


of  the  adults  just  mentioned.     Larvae  were  watched  for  twenty  days, 
during  which  time  they  did  not  reach  full  growth. 

The  extreme  shortness  of  this  June  o-eneration  is  sio-nificant.  It 
accounts  for  the  fact  that  swarms  of  mosquitoes  may  develop  upon 
occasion  in  surface  pools  of  rain  water,  which  may  dry  up  entireh^  in 
the  course  of  two  weeks,  or  in  a  chance  bucket  of  water  left  undis- 
turbed for  that  length  of  time.  Further,  the  shortness  of  this  genera- 
tion was,  while  not  unexpected,   not  at  all  in  accordance  with  any 


28 

pul)lislu'(l  statrnionts  as  to  tho  length  of  life  of  an}'  immaturo  mos-  ■ 
(juito  of  any  sju'cics.     But  thcso  pii})lisln'd  statements,  as  jncvioiisly  | 
shown,  were   nearly   all   })ase(l   uj)()n    o))servations  made    in  a  eolder 
climate  and  in  tlie  month  of  May. 

lirmtirls  on  otluv  sjfecies  (tf  Vulex. — The  writer  is  inclined  to  ]>elieve 
that  (uh^x  Uvnhn'hynchux  (tig.  .5)  is  more  or  less  specifically  the  sea- 
coast  mosquito  of  the  Atlantic  seaboard;  that  is  to  say,  it  is  the 
mos(juito  in  this  j)art  of  tlie  country  wliicii  is  ai»le  to  breed  and  prefers 
to  bleed  in  the  luackisli  swamps  wliicli  are  occasionally  overflowed  at 
hi«rh  tide,  it  has  been  found  by  Mr.  ('.  W.  Johnson  at  Avalon, 
Ant^desea,  and  At iantic  City,  N.  J.;  by  the  writer  at  Far  Kockawav. 
Ameriranx'tl.  and  <>ii  liie  b(':i<li  at    Staten   Island.  New  "^'ork  :  bv  Mr. 


^' 


Fig.  5. — Cuhjc  l:iiiii>rh!/iichu.s :  Female,  showing  the  sliort  palpi  which 
distinguish  Ciilrx  from  Aitt>itfiili.<:  {t>^\Xh^^^\  front  tarsjil  claw  at  right — 
enlarged  (original). 

Barber  at  Chesapeake  Beach,  Md..  and  a^fain  l)v  Mr.  Johnson  at  St. 
Aut^ustine  and  Charlotte  Harbor,  Fla  Other  species,  like  i'ulcx pim- 
ge}if<^  are  seen  at  seaside  resoits.  but  it  is  probable  that  these  breed 
back  of  the  coast  in  fre.sh  water.  This  ditierence  in  breeding  habit  is 
very  mark(»d  on  thi*  east  coast  of  Staten  Island.  The  people  there 
distinguish  ])etween  the  browndegged  mo.scjuitoes  and  the  ring  legged 
mo.scpiitoes,  the  former  being  (\  pu?ige?is,  which  breeds  in  the  hilly 
ponds  and  swamps  })ack  of  the  bluffs,  and  the  latter  being  ('.  t(Siu<t- 
rJn/ncas^  which  breeds  in  the  brackish  marshes  below  the  blulTs.  Dr. 
A.  1).  Hoi)kins  .states  (Bulletin  17,  new  series,  Div.  Entom.,  Dept. 
Agric.)  that  what   is  j)roba]>ly  this  spinies  apj)arently  l)reeds  in  West 


29 

Virginia  in  pools  and  small  streams  fed  from  coal-iiiiiic  draiimuc  tlii^ 
water  of  which  contains  a  laro^i*  ]icrccntati(*  of  sulphate  of  iron. 

Cfflc.r  'nnphjer  has  ])con  found  hy  Mr.  Pratt,  of  this  ofKcc,  brecdinc^ 
in  privy  vaults  in  Alexandria,  Va.,  and  this  species  is  likely  to  be  the 
one  found  usually  in  such  places  where  the  water  is  fouhnl  with  decom- 
posing or  excreted  animal  matter. 

CuleiP  taeiilatus  is  said  by  Dr.  Veazie,  of  New  Orleans,  to  be  the 
so-called  ''day  mosquito"  of  New  Orleans;  that  is,  the  form  which 
flies  and  bites  in  the  daytime.  This  stattMuent  is  corro])orated  to  a 
certain  extent  ))y  Dr.  St.  George  Gra}',  of  St.  Lucia,  British  West 
Indies,  who  writes,  under  date  of  August  12  last: 

I  have  made  some  observations  on  the  hours  at  which  the  different  species  are 
most  industrious,  and  find  that  most  mosquitoes  have  regular  feeding  times.  For 
instance,  C.  ixniatus  is  very  vigorous  and  troublesome  in  the  early  afternoon  (between 
noon  and  3  p.  m).  Then  she  usually  takes  a  rest,  and  renews  her  attacks  at  9  or 
10  p.  m.  During  the  morning  it  can  be  found  resting  on  walls  and  clothing,  particu- 
larly dark-colored  clothing,  and  is  easily  caught. 

The  distribution  of  the  species  of  Culex  in  the  United  States. — In 
preparing  Bulletin  No.  4  the  writer  was  at  pains  to  borrow  all  of  the 
mosquitoes  from  the  collections  of  such  entomologists  as  he  supposed 
had  saved  specimens  in  this  family  and  placed  them  in  the  hands  of 
Mr.  Coquillett  for  stud3\  The  material  received  was  not  large,  since 
mosquitoes  are  difficult  to  preserve  satisfactorih^  in  a  collection,  and  it  is 
an  inexplicable  fact  that  as  a  rule  collectors  do  not  save  such  extremely 
common  things  as  mosquitoes.  Yet  he  was  able  from  Mr.  Coquillett's 
work  on  the  specimens  received  and  on  those  already  contained  in  the 
national  collection  at  Washington  to  show  several  interesting  points. 
As  is  the  case  with  man}^  other  species  of  Diptera,  most  of  the  differ- 
ent forms  were  found  to  be  ver}^  widespread.  The  whole  group  has 
little  or  no  faunistic  value;  that  is  to  say,  different  climatic  conditions 
and  other  environmental  factors  do  not  limit  the  range  of  the  species 
as  they  do  with  those  of  other  groups.  It  was  thus  found  that  some 
of  the  commoner  forms,  like  O.  co?isohri7ius,  C.  excitans^  C.  pet'turbans^ 
and  C.  p)ostlcatus,  and  C.  pungens,  were  found  almost  all  over  the 
country,  from  New  England  to  Texas  and  even  to  southern  California, 
so  that  in  almost  an}^  given  locality  in  the  United  States  one  would  be 
able  to  find  all  of  these  common  species  of  Culex,  with  two  or  three 
species  of  other  genera  and  possibly  two  oT  three  other  species  of 
Culex.  Since  the  publication  of  the  bulletin  (No.  4),  other  localities 
of  distribution  have  been  ascertained,  and  the  following  list  indicates 
such  actual  localities  as  have  come  to  our  notice.  Persons  interested 
will  observe  several  points  worth  noticing'  in  the  list  which  follows. 
Certain  species  seem  to  be  rare,  while  others  are  very  common,  in 
addition  to  being  widespread.  It  seems  from  the  list  that  Cidex  con- 
sohrimts  is  a  more  northern  form;  that  is,  it  comes  nearer  being 
restricted  to  a  boreal  habitat  than  an}^  of  the  other  species.     It  is  one 


30 

ol'  tlu'  two  >|M(ir>  wliicli  wo  li:i\<'  iioiii  Alaska.  T\io  othcM'  Alaskan 
loiiii  wliicli  lias  Im'cm  (ii'tonniiMMl.  iiaiii('l\ .  ( '.  ////y^/V///.  oxtonds  south 
to  New  Mexico.  ( leoi-cria.  and  the  island  of  Jamaica. 

('n/t.r  fiinnitns,  accoidiriii*  to  Ml'.  Tlicohald,  has  a  wide  tropical  and 
subtropical  dist i-il)ution.  occuriin*:^  in  \N'cst  Africa.  Indui.  South 
Europe,  and  Kast  and  West  Indies,  hut  never  in  the  north  or  south 
cold  temperate  /ones. 

Cri.KX    CONSOHKIM  S   I  )('>\  . 

Ihihitat:  Whit«'  Mc.uiituiii.s,  X.  II.;  lU-verly,  Mius^.,  SeptemlM-r  L'8  (Nat.  MiiB.) 
Catpkill  Mniiiitaiiis,  (Jreeiie  (^mIlty,  N.  Y.,  2,5(X)  feet  (Howard);  Illinois, 
March  *JI,  .Vpril  L't>,  May  <>,  OctolnT  1«  (Xa«on);  St.  Anthony  Park,  Minn., 
April,  May,  on  snow  (Lu^er );  Saskatchewan  Uiver,  British  America;  Sqjith 
I)ak«ita  (  Xat.  Mus. );  Lincohi,  Xe))r.,  May,  Septeniln'r  (Brnner);  Colorado 
(Xat.  Mas.);  Los  Angeles,  Cal.,  Fehrnary  ( C'cxinillett );  Ar^'ns  Mountains, 
Cal.,  April  (Nat.  >rus.);  Santa  Fc,  X.  Mcx.,  July  (Cockerell);  Xew  Orleanp, 
I^.,  Xoveniher  (Thayer);  Ottawa,  Canada,  May  i  ITnwMrdi;  Suniniit,  X.  J. 
(Holmes);  Trenton,  Ontario,  May  24  (Fletcher). 

C'ULKX  KXciT.ws  Walk. 

Habitat:  New  Redfdnl,  Mass.  (Jolmsoii);  Lincoln,  Xehr.,  May  (Bniner);  Santa 
Fe,  N.  Me.x.,  July  (Cockerell  i;  La^^'an,  British  Columbia  (Wirkham). 

Cri.EX  KX(  KCciANs  Walk. 

Habitat:  Ithaca,  N.  Y.,  July  U  (Comstock). 

(.n.K.x  FAsciATCs  Fa))r. 

IIal)itat:  (ieorjria,  .Xugust  (Coquillett);  Natchitoches,  1^.,  October  6  (Johnson); 
Isle  of  Pines,  West  Indies  (Scudder);  Kingston,  Jamaica,  July  13  (Johnson )j 
New  Orleans,  La.,  November  (Thayer);  ea.stern  Texaj*  (Woldert);  Cuba 
(I.^zear). 

CULEX  IMPIOER  Walk. 

Habitat:  White  Mountains,  N.  IL;  Beverly,  Mass.,  May  24,  June  2  (Nat.  Mus.); 
Tthaca,  N.  Y.,  July  l»  and  17,  August  2S;  Wilmuth,  N.  Y.,  June  10  (Comstock); 
Saskatchewan  River,  British  America  ( Nat.Mus. ) ;  Minnesota(  Lugger ) ;  Loudoun 
County,  Va.,  August  26  (Pratt):  Tyrone,  Ky.,  July  14  ((iarman);  Georgia 
(Nat.  Mus. ) ;  Mesilla,  N.  Mex.  (Cockerell) ;  Isle  of  Pines,  West  Indies  (Scudder) ; 
Portland,  Jamaica  (Johnson);  District  of  Columl)ia,  Septeml)er  12  (Barlx^r); 
Alexandria,  Va.  (Pratt);  Ogdensburg,  N.  Y.,  Jiiiie  M  (Howard);  Middletown, 
Conn.,  June  (Davis);  Ottawa,  Canada,  May  .SI  (Howard);  Chats  liapids,  Que- 
I)ec,  May  24  (Fletcher);  Buckeye,  Wash.  (Nat.  Mus.);  Stikine  River,  British 
Columbia  (  Wickham). 

CULEX  rEKTCRBANS  Walk. 

Habitat:  lakeland,  Md.,  August  8  (Pratt);  Virginia,  August  17  (Pergande);  Tick 
Island,   Fla.,   May  12  (Johnson);  Texas  (Nat.Mus.);  Bay  anion,  Porto  Rico 
January  (Busck);  District  of  Columbia,  September  1-5  (Barber);  St,  Elmo,Va.| 
June,  July  (Pratt);  Cu))a  (Lazear). 
Cri.EX  posTicATCs  Wicd. 

HaV»itat:  M(»ntgomery   County,    Pa.,    July    17    (Johnson);   Texas    (Nat.Mus.); 
Loud«»nn  County,  Va.,  .Vugust  (Pratt);  Roanoke,  Va.,  October  (Thayer);  Dis- 
trict of  C?>lumbia,  June  10  (Bar}>er). 
Ci  i.i;\  iTNOE.xs  Wie<l. 

Habitat:  White  Mountains,  N.  IL;  Beverly,  Ma.«is.,  Sep  em  er  5;  Cambridge, 
Ma.»<s,,  September  Ifi  to  November  o;  Boston,  Ma.«s. ;  Baltimore,  Md.,  Novem- 
>)er5  (Nat.  Mus.),  Novend>er  26  (Lugger);  Charlton  Heights,  Md.,  December  1 
(Pratt);  District  <»f  Columl)ia,  January  .SO,  March  5,  May  6  and  15,  June  2%, 
July  11,   August,  OctoWr  10,   15,  25,  and  31,  November  4,  8,  13,  16,  and  23, 


31 

Docemlier  2S  (rVrjjando');  Itliaca,  N.  V.,  INFay  I't),  July  17,  Anjuinf  L'S  (Coin- 
stock);  Illinois  (Nason);  ^Minnesota  (Ln^r^rn);  Lincoln,  Nehr.,  Scplcinln'r  20 
(Bruner);  lj(.\xinu:t()n,  Ky.,  NommuIut  10  ( ( iannaii );  New  Orleans,  La.,  Decem- 
ber 17  (Howard);  San  Antonio,  Tex.,  May  '>  (Marlatt);  (Jeor^'ia,  An^Mist 
(Coquillett) ;  Portland,  Jamaica,  (Johnson);  Mexico  City  (Rarrett);  District 
of  Cohnnbia,  Anjrnst  22,  28,  Sej>tember  1  (Barber);  Jackson,  Va.,  October 
(Thayer);  Woodstock,  Va.,  June  (TVatt);  Newport  News,  \'a.,  October 
(Thayer);  Stillwater,  Okla.,  June  (Botrue);  Philadelphia,  Pa.,  (Woldert);  New 
(Orleans,  La.,  Jnne  (Veazie);  eastern  Texas  (Woldert);  Snnnnit,  N.  J.,  ]May 
(La  Rue  Holmes);  ^Nliddletown,  Comi.,  June  (Davis);  Cuba  (Lazear). 

CULEX    SIGNIFER   Co(]. 

Habitat:  District  of  Columbia,  June  (Coquillett),  jNIay,  August  (Barber);  St. 
Elmo',  Va.,  June  4  (Pratt). 

CULEX    STIMULANS    Walk. 

Habitat:  White  ^Mountains,  N.  H.;  Beverly,  IVIass.,  June  2,  July  9;  Cambridj^e, 
Mass.,  May;  Jamaica  Plain,  Mass.,  August  25  (Nat.  Mus.);  Baltimore,  Md. 
(Lugger);  Illinois,  August  1,  September  15,  October  5  (Nason);  Agricultural 
College,  Mich.  (Gillette);  Saskatchewan  River,  British  America  (Nat.  ]\[us. ); 
Lmcoln,  Nebr.  (Bruner);  Colorado  (Nat.  Mus.);  Ithaca,  N.  Y.,  June  LS,  18,  29, 
July  14,  August  28;  Wilmuth,  N.  Y.,  June  10  (Comstock) ;  Georgia  (Nat.  Mus. ) ; 
Bladensburg,Md.,May  27  (Barber);  St.  Elmo,  Va.,  June  5  (Pratt);  District  of 
Columbia,  September  (Barber),  June  10  (Miss  L.Sullivan);  Ottawa,  Canada, 
June  1  (Howard);  Ogdensburg,  N.  Y.,  June  3  (Howard);  Rochester,  N.  Y. 
June  (Ewers);  Summit,  N.  J.,  May  (La  Rue  Holmes);  Middletown,  Conn., 
June  (Davis);  Mesilla,  N.  Mex.,  October  26  (Cockerell);  Tacna,  Ariz.,  April  13 
(Hubbard);  Juarez,  Mexico,  May  12  (Cockerell);  Summit,  N.  J.  (Holmes). 
CuLEx  T^xiATus  Wied. 

Habitat:  New  Orleans,  July  (Veazie);  Cuba  (Lazear). 

CULEX   T.ENIORHYNCHUS    Wied. 

(Not  the  Cidex  txniorhynchus  Wied.  of  Arribalzaga.) 
Habitat:  Maine,  August;  Beverly,  Mass.,  June,  September  15  (Nat.  Mus.); 
Avalon,  Anglesea,  and  Atlantic  City,  N.  J.,  July  10  to.  29  (Johnson);  Far 
Rocka way.  Long  Island,  N.  Y.,  August  30*  (Howard);  District  of  Columbia 
(Pergande);  Georgia  (Nat.  Mus.);  St,  Augustine  and  Charlotte  Harbor,  Fla., 
July;  Portland,  Jamaica  (Johnson);  Chesapeake  Beach,  ]\Id.  (Barber);  Balti- 
more, Md.  (Thayer);  Plymouth,  N.  C.  (Thayer);  Galapagos  Islands,  February 
1—4  (Snodgrass). 

CULEX    TARSALIS  Coq. 

Habitat:  Argus  Mountains,  Cal.,  April;  Folsom,  Cal.,  July  3  (Nat.  Mus.). 
CuLEX  TRisEEiATus  Say, 

Habitat:  White  Mountains,  N.  PI,  (Nat,  Mus,);  Delaware  County,  Pa,,  June  12 
(Johnson);  Washington,  D,  C,  May  5  and  June  10;  Loudoun  County,  Va, 
(Pratt);  Near  Baltimore,  Md.  (Thayer);-  Roanoke,  Va,,  October  (Thayer); 
Middletown,  Conn,,  June  (Davis);  New  Jersey  (Woldert). 

THE    BIOLOGY    OF    ANOPHELES,    WITH    GENERAL    EEMARKS. 

So  far  as  the  writer  can  ascertain,  no  detailed  illustrated  account  of 
the  early  stages  of  any  species  of  Anopheles  had  been  published  before 
his  paper  in  the  Scientific  American,  above  referred  to.^  He  con- 
ceived it  to  be  nearly  as  important  that  the  ma'arial-bearing  mosquitoes 
should  be  readily  recognized  in  their  early  stages  as  in  their  adult  con- 
dition.    He  was  very  fortunate  in  April  of  the  present  year  in  being 

^  See  appendix. 


82 

a})lr  to  socuro  a  l:ii'^'"o  iiuiiiIht  of  t^ravid  fiMiialos  of  AiutjthiliH  tpiadri- 
imiriihittis  Say  tliroutifh  the  almiulaiici'.  of  this  species  near  the  home  of 
one  of  liis  assistants.  Mi.  Pratt,  in  Virj^inia,  a  few  niiU's  from  Wash- 
in<,^ton.  Mr.  Pratt  was  enthusiastic  and  assichioiis  in  coUectin*^  living 
a(hdt>.  and  th.'se  were  kept  in  eontinement  and  their  offspring  reared 
in  hirge  water  jars  (hiring  April  and  May,  llMHj.  It  may  he  mentioned 
here  that  this  species  is  without  (loul)t  identical  with  the  European 
Aitnjthihs  iiHiridijh  nnls  Meigen,  a  fact  which  Mr.  ('(xjuillett  has  always 
strongly  suspected,  although  he  had  no  P^uropean  material  with  which 
to  c()mi)are  our  American  specimens.  Dr.  W.  S.  Thayer  saw  A.  macu- 
lijh  tuus  in  (Jrassi's  laboratoi'v  in  Italy,  and  on  his  return  to  this  coun- 


Fn..  <  .—  .\ii<>iiliilis  i/iKiiiriiKtii  iilntii.-:  A<llilt.  ii'.hIc  jit  Irlt,  f( 


tilt  riirlit— tiiljirmd  lorigiiial). 


try  tokl  tlie  writer  that  he  thought  the  two  forms  identical.  The 
(juestion  has  now  ])een  definitely  settled  by  Mr.  F.  V.  Theobald,  of 
Kngland.  who  is  monographing  the  mos(juitoes  of  the  world  for  the 
British  Museum,  and  who  writes  us  under  date  of  May  28,  lOUO,  that 
he  has  studied  a  large  series  of  A.  (jvadrivtnculatius  received  from 
Canada  and  that  *'they  (^xactly  tally  with  ^1.  7/uiculi'pe7i7iis,''^ 


I, IKK    HISTORY    OF    AXOPHEI.HS    tH'ADRIMACULATUS. 

TnK  ADiLT. — The  acc()m})anving  dlustrations  (figs.  T),  7.  S)  will  show 
vciv  wrll  the  gjMKMai  api)earance  of  the  adult  insect.     It  is  a  rather 


33 


lai'sio  in()S(|iiit<)  and  is  vorv  r)l()()(l-lliirsty.  It  Is  attracted  to  the  house 
in  iiuiidHMs.  'VUv  dillcrciu'cs  Ix'twccn  the  mah's  and  t'cmah's  arc  well 
brought  out  in  the  iUustratioiis,  and  the  strik*m»;-  feathciT  Jinteniui'  and 
palpi  of  the  male  ivudcr  it  very  conspicuous.  The  winj^-  niarkinos  arid 
the  color  t)l'  tlie  pal})!  ditrcrciitiate  this  s})ecies  from  our  other  s})ccies  of 
Anopheles,  and  the  lonj>-  pjilpi  of  the  female  at  once  distinguish  it  from 
all  species  of  Culex. 


Fig 


-Resting  positions  of  Culex  (at  left)  and  Anopheles  (at  right),  enlarged  (redraAvn  from  a  rough 
sketch  published  in  the  British  Medical  Journal). 


nesting/ position. — Owing  to  the  publication  of  a  field  sketch  made 
at  Sierra  Leone  by  a  member  of  the  Ross  expedition,  and  which  is 
here  reproduced,  the  writer  has  been  much  interested  in  watching  the 
resting  positions  of  the  adult  insects.  He  finds  that  when  resting  upon 
a  horizontal  surface — such  as  the  ceiling  of  a  room  or  the  covering  of 
the  breeding  jars — the  insect  clings  with  its  four  anterior  legs  in  a 
nearly  perpendicular  position,  its  beak  thrust  forward  toward  the  sur- 
face to  which  it  clings.  The  hind  legs  are  frequently  in  motion,  but 
as  a  rule  hang  downward  with  more  or  less  of  a  bend  at  the  knee  joint 
(femero-tibial  articulation).  When  resting  upon  a  perpendicular  sur- 
face, however — such  as  the  side  wall  of  a  room  or  the  side  of  a  breeding 
jar — the  body  is  held  only  at  a  comparatively  slight  angle  from  the 
surface.  Sometimes  it  is  nearly  parallel  with  the  surface.  At  other 
times  it  assumes  an  angle  of  10^  to  20^  (occasionally  even  as  great 
an  angle  as  30°  to  40°),  the  proboscis  being  held  nearly  in  a  line  with 
the  body.  Here  again  the  insect  supports  itself  by  the  four  anterior 
legs,  the  hind  legs  dangling  down  with  more  or  less  of  a  bend  at  the 
3949 3 


84 


knee.  This  j>ositi(Mi  is  coininon  t<>  hotli  iiuilcs  and  fonialos.  and  is  illiis- 
tnited  at  rii,'.  s.  When  tho  body  is  held  parallel  it  will  generally  l)e 
found  that  one  of  the  middle  or  hind  legs  has  been  broken  off.  The}^ 
Hre  verv  delieate  and  reatlilv  break. 


Fi«;.  S. — Aftiial  resting  f»f)sltioiis  i.i"  A.  'jint'irimnailatiis  on  a  horizoiiLHl  reiling^  and  on  aside  wall, 
drawn  from    life — enlarged  (original). 

The  writer  has  taken  the  li))erty  of  having  fig.  0  engraved  from  a 
drawing  sent  him  l)y  Mr.  C.  O.  Waterhouso  of  the  British  Museum. 
Mr.  Waterhouse  made  the  drawing  himself  and  wrote:   "Whatever 


^'H'.  0.— Anopheles  at  left,  Cnlox  at  right— enlarged  (drawn  by  C.  O.  Waterhouse). 

Miay  be  the  attitude  of  Anopheles,  it  is  all  in  one  line.     Culex  is  angu- 
lar, humi)ba(ked.*' 

Xoteaffomd,. — The  peculiar  hum  of  the  mosquito  is  well-known. 
There  is  a  distinct  difference  l>etween  the  hum  of  Anopheltii  quadrlma- 


35 


oiJafiis  and  that  of  i\\v,  comnioii  .s])(M'ios  of  C'lilcx  in  that  the  foi-iiior  is 
noticeably  lower  in  tone.     The  note  of  Culex  as  it  approaches  the  ear 


Fig.  10. — Anopheles  quadrimaculatus:  Group  of  4-1  eggs  deposited  by  a  single  female  as 
tliej-  appear  resting  naturally  on  the  surface  of  the  water— enlarged  (original). 

is  high  in  pitch ;  that  of  Anopheles  is  certainly  several  tones  lower 
and  of  not  so  clear  a  character.  In  quality  it  is  something  between  the 
buzzing  of  a  house  fly  and  the  note  of  Culex.  Mr.  Pratt  states  that  he 
can  at  once  distinguish  the  two  genera  in 
this  way  as  he  is  sitting  reading  in  the 
house,  and  the  writer  feels  quite  sure  after 
listening  to  them  in  breeding  jars  that  the 
statement  is  correct. 

These  observations  have  been  made  with 
an  abundance  of  material,  nearly  100  adults 
having  been  under  observation. 

The  eggs. — The  well-known  and  often- 
mentioned  boat-shaped  masses  of  eggs  of 
Culex  are  not  even  remotely  resembled  by 
the  Anopheles  ovipositions,  and  the  indi- 
vidual eggs  are  equally  dissimilar.  In  the 
accompanying  illustration  (fig.  10)  the  egg 
mass  of  Anopheles  is  illustrated  for  com- 
parison with  fig.  1.  In  Culex  from  200  to 
100  eggs  are  laid  in  a  mass  ordinarily  shaped  like  a  pointed  ellipse,  con- 
vex below  and  concave  above,  all  the  eggs  perpendicular,  and  stuck 


Fig.  11.— Anopheles  quadrimaculatus: 
Egg  from  below  at  left,  from  above 
at  right — greatly  enlarged  (origi- 
nal). 


8(> 

cloiicly  tojift'thiT  at  the  .sides  )»y  hoiiie  <riiiniiiy  sec- rot  ion,  and  arranged 
ill  rows.  'I'lie.  mass  with  Anopheles,  however,  is  laid  loosely  upon  the 
siirfaee  of  the  water,  each  v^rg  lyinj^  upon  its  side  instead  of  being 
plaeed  iij)on  its  end  as  in  tln^  ej;«r  mass  of  C'ulex.  They  are  not  attaelied 
togetlu'r  except  that  they  naturally  Hoat  elose  to  each  other  and  there 
are  from  40  to  U)()  ej^jrs  in  each  lot.  In  ('ulex  'jyiuajrixH  the  individual 
e^ir  is  n.7  mm.  loiii^-  and  (>.  10  mm.  in  diameter  at  the  base.  It  is 
slender,  luoadri-.  and  blunt  at  the  ]>ottom,  slenderer  and  more  pointed 
at  the  tip.  Tiie  tip  is  always  dark  t^-rayish  Ijrown  in  color,  while  the 
rest  is  dirty  white.  Th(»,  ejrir  of  Anopheles  when  seen  from  above  is 
of  II  rather  re»,'-ular  elliptical  outline,  the  two  ends  having  practically 
the  same  shape;  seen  from  the  side,  it  is  strongly  convex  below  and 
nearly  i)laiu'  al)ove;  seen  from  below,  it  is  dark  in  color  and  when 
examined  with  a  hi<rh  power  is  seen  to  be  covered  with  a  reticulate 
hexa«4()nal  sculpturing.  At  the  sides,-in  the  middle,  there  appears  a 
clasping  nuinbrane  with  many  strong  transverse  wrinkles.  Seen  from 
above,  the  v^^'^^  is  l)lack  except  for  a  clasping  membrane  which  nearly 


Fiti.  V2.—Annphcks  qiuulrimacidatuf:  Newly  liulched  larvH— greatly  enlarged  (original). 

meets  on  the  middle  line  in  the  middle  third  of  the  ])ody,  but  retires  to 
the  extreme  sides  for  the  anterior  and  posterior  thirds.  At  each  end 
the  color  is  lighter,  with  a  group  of  from  5  to  7  minute  dark  circular 
spots.  It  is  O.oT  mm.  long.  Eggs  laid  April  2*)  hatched  April  30. 
Others  laid  .May  lo  and  U  hatched  :\lay  Kl  and  17. 

The  I.ARVA. — The  lar\ais  cpiite  as  unlike  that  of  .Culeo' j}u?i(/e}is  »s 
is  the  i'^f<f.  It  differs  in  structure,  in  its  food  hal)its.  and  in  its  cus- 
tomary position  so  markedl}'  that  it  can  at  once  be  distinguished  with 
the  utmost  ease.  The  larva  of  Culex,  it  will  be  remembered,  comes 
to  the  surface  of  the  wtitcu*  to  ])reathe,  thrustini^  its  breathing  tube 
throui^h  the  surface  laver  and  holding  its  l)odv  at  an  angle  of  about 
45  degrees  with  the  surface  of  the  w^ater.  While  in  this  position  iti» 
mouth  parts  arc  in  motion  and  it  is  taking  into  its  alimentary  canal 
such  minute  ])articU\s  as  may  be  in  the  water  at  that  depth,  l)ut  these 
are  naturally  few  in  iunn])er  and  the  larva  descends  at  frequent  inter- 
vals toward  the  liottom  to  feed.  The  want  of  oxygen,  however,  causes 
it  to  wriggle  up  again  to  the  surface  at  very  frequent  intervals.     Its 


37 


specific  gravity  soonis  crroatcM-  tluin  tluit  of  water,  so  that  it  roaches  the 
surface  only  ))y  an  eH'ort,  and  th(^  writci-  lias  already  pointed  out  in  the 
case  of  (\  j>un(/<'ns  tliat  when  the  lar\a  l)cconl(^s  (MifcM'hh'd  and  is  not 
strong  enough  to  wriggle  up  to  the  surface  it  drowns.  Feeding"  as  it 
does  at  the  bottom  upon  t!M>  heavier  })artich*s  which  sink,  its  specific 
gravity  is  explained.  'V\\v  lar\a  of  Anophrhs  quddrinHicuJdf^i.s^how- 
^^WidV^  habitually  remains  at  the  sui'face  of  the  water.  Its  l>reathing 
tube  is  very  nuich  shorter  than  that  of  Cuh^x  and  its  Ixxly  is  held  not 
at  an  angle  at  the  surface,  but  practically  parallel  with  the  suifaee  juid 
immediately  below  the*  surface  lilm.  so  that  portions  of  its  head,  as 
well  as  its  breathing  tii))e,  are  practically  out  of  the  water.  Its  head 
rotates  upon  its  neck  in  a  most  extraordinar}-  way,  so  that  the  larva 


Fig.  13. — Anopheles  quadrimaculatiis  and  Culex  imngens:  Half-grown  larva  at  left  and  in  center,  in 
comparison  with  half-grown  larva  of  Culex  pungens  at  right  (figure  at  left  has  been  cleared) — 
greatly  enlarged  (original). 

can  turn  it  completely  around  with  the  utmost  ease  and  feeds  habitu- 
all}^  with  the  under  side  of  the  head  toward  the  surface  of  the  water, 
whereas  the  upper  side  of  the  body  is  toward  the  surface.  In  this  cus- 
tomary resting  position  the  mouth  parts  are  working  violently,  the 
long  fringes  of  the  mouth  parts  caiLsinga  constant  current  toward  the 
mouth  of  particles  floating  on  the  surface  of  the  water  in  the  neigh 
borhood,  which  thus  gradually  converge  to  this  miniature  maelstrom 
and  enter  the  alimentar}^  canal.  The  spores  of  algji?,  bits  of  dust, 
minute  sticks,  bits  of  cast  larval  skins,  ever^^thing  in  fact  which  floats, 
follov/  this  course,  and,  watching  the  larva  under  the  microscope,  the}^ 
can  plainh^  be  seen  to  pass  through  the  head  into  the  thorax  until  they 


38 


aro  ohscurod  ])y  tlic  dnvk  color  <  f  the  inscM-t's  ))j\(k.  Orcjisioiially  too 
lar«r«'  Ji  fra*ruHMit  to  Ik'-  swallowed  with  case  cloofs  the  iiiouth.  Some- 
tiiiirs  it  i'nt«Ts  the  iiKuith  and  sticks.  In  such  cases  the  head  of  the 
hirva  revolves  witii  lij^htniiii^-likc  iiipidity  and  the  fragment  is  nearly 
alwa\-^  dis*;ort»'cd.  althoiij^h  sometimes  it  is  swallowed  with  an  evident 
ctioit.  Since  the  Aiioplielcs  lar\a  t'ct'ds  only  iH)on  these  li»i"ht  tloatin^r 
particles,  its  specitic  t^ravity  is  nearly  that  of  the  wat<'r  itself  arid  it 
suppoits  this  JMnizontal  position  just  heneath  the  surface  tilin  with 
comi)arative  eas<'.  and  in  fact  without  eti'ort,  the  tension  of  the  surface 
—  Him     itself    being 

hardly  needed  to 
h(dd  it.  It  requires 
an  etlort  in  fact  for 
the  Anopheles  larva 
to  descend  (which  it 
apparently  n  e  v  e  r 
does  up  to  the  period 
of  the  final  larval 
stage,  except  when 
alarmed),  while  it 
requires  an  etiort 
for  the  Culex  larva 
to  ascend. 

Structurally  the 
ditferences  between 
the  h  a  1  f  -  g  r  o  w  n 
larva?  of  Culex  and 
Anopheles  are  well 
shown  at  tigs.  18, 14, 
and  15.  The  great 
size  of  the  head  of 
Culex,  as  conti-asted 
with  the  small  head 
of  Anopheles  is  a 
most  striking  differ- 


Fio.  H.— Figxireat  lop.  half  grown  larva  of  Anopheles  in  feeding  posi. 
lion,  jusl  biMuatli  surface  lilni.     Figuri"  at  bolt«>m,  half  grown  larva    euce 
of  CnK'x  in  hrt-athing  jjosilion— greatly  enlarged  (original).  i 


r  h  e     y  (» r  y 
respiratory 

siphon  (as  Miail  calls  it)  of  Culex  contnists  markedly  with  the  short 
one  of  Anoi)heles.  Tlie  arrangement  of  the  hairs  is  entirely  diti'erent, 
\hv  ))ranching  of  the  hairs  of  Anopheles,  as  contrasted  with  the  simple 
hairs  of  Culex  and  the  little  paired  stur-shaped  (apparently  branchial) 
tufts  on  the  dorsum  of  Anopheles  are  entirely  al)sent  with  Ciil(\\.  The 
flaps  at  the  tail  end  of  the  body  are  similar  in  number,  but  are  held  in 
asomewiiat  ditb'rent  position. 


39 


The  larvae  first  studied — thost^  wliicli  luitclicd  from  the  cj^^os  on 
April  30 — grow  very  slowly  for  a  nuinbor  of  da3's.  'I'll is  was  partly 
owing"  to  cool  woathor  in  the  early  part  of  May,  and  partly,  I  believe, 
to  the  absence  of  proixM-  food.  They  were  reared  in  ghiss  jars  of  water, 
with  sand  at  the  bottom  and  a  willow  twig  rooting  in  the  sand.  As 
above  noted,  they 
swallowed  every 
small  particle  floating 
on  the  surface  of  the 
water,  and  the  dark 
coloration  shown  in 
tig.  14  was  largely- 
due  to  the  fact  tha 
most  of  these  fooc 
particles  were  dark 
colored.  About  the 
10th  of  May,  the 
larvae  having  passed 
through  two  molts, 
a  small  quantity  of 
the  green  alga?  grow- 
ing on  the  lily  ponds 
on  the  Department 
grounds  w^as  placed 
in  the  jar.  ^  The  larvae 
commence  to  thrive 
much  better,  grew 
rapidly,  and  the  gen- 
eral color  of  the  body 
changed  to  green. 
The  description  of 
the  habits  given 
above  held  well  until 
after  the  last  molt 
preceding  the  change 
to  pup^e.  In  this  final 
larval  stage,  as  shown 
in  fig.  15,  the  diameter  fig 
of  the  thorax  became 
much  greater  in  com- 
parison with  the  rest  of  the  body.  The  larva  was  less  marked,  more 
inconspicuous,  and  altered  its  feeding  habits  to  some  extent.     After 

^ These  algae  were  studied  by  Mr.  A.  F.  Woods,  of  the  Division  of  Vegetable  Phys- 
iology and  Pathology,  who  informed  me  that  the  larger  part  belong  to  a  species  of 
the  genus  QEdogonium,  but  that  there  was  also  quite  a  large  amount  of  a  species  of 
Cladophora,  with  some  Spirogyra.     There  was  also  some  of  the  blue  green  Oscilaria. 


15.— Anopheles  qaadrimacalatus:  Full  grown  larva  in  feeding 
position,  seen  from  above  (head  reversed,  in  feeding  position); 
dorsal  side  of  head  above  at  right— greatly  enlarged  (original). 


40 


ronmiiiin^at  tho  surface  of  tho  wjitor,  feeding,  as  before,  upon  floating 
particles  for  some  Hme,  it  would  wriggle  violently  and  descend  to  the 
hottoni,  where  it  would  remain  frecpiently  as  long  as  two  minutes 
before  reaseending  to  the  top.  Its  appetite  was  evidently  so  great 
that  it  was  not  satisfied  with  the  floating  particles,  and  when  it  descended 
to  the  }M)tt<)in  it  mouthed  the  jKirticles  of  sand,  evidently  swallowing 
the  slime  on  tiie  little  stones  and  frequently  even  picking  up  (juite  a 
a  large  s:md  pehl>le  and  th«Mi  droj)))ing  it  again.  In  this  stiige  the  indi- 
\i(lual  which  grew  most  ra})i(lly  remained  only  four  days,  and  trans- 
formed to  ])U})a  on  the  morning  of  the  1 7th.  after  a  lar\al  exist4»nce  of 
sixteen  days.  The  accompanying  iigures  of  the  larva'  have  been  dniwn 
witii  such  caic  that  detailed  desciiption  will  ])e  unnecessary.  They 
w«'re  drawn  from  life  under  the  compound  microscope.  Some  of  the 
stiuctures  are  puzzling,  notably  the  organs  occuring  on  the  dorsum  of 
the  a)>dominal  segments,  shown  most  plaiidy  in  tig.  15,  and  w  hich  look 
as  though  they  might  ]ye  spiracles  until  they  are  examined  under  a  high 
power  in  the  cast  skin.  The  writer  d(K's  not  care  to  risk  an  expression 
of  opiidon  as  to  their  function,  although  possildy  it  is  known,  and  they 
possibly  occur  in  other  acjuatic  dipterous  larva\  In  the  early  stages  of 
the  larva'  they  resend)le  minute  hranchial  tufts,  lait  no  tracheal  con- 
nection has  been  found. 

1  UK  I'UPA. — The  accompanying  figure  (tig.  16)  well  represents  the 


Fig.  16. — I'upu  (if  Ciilr.r  jni)ii;t  IIS  at  U-ft:  juipji  of  Annpfirirs  qumlrimaculalus  &t  risiht — prn^atly  enlarged        i 

(original).  j 

difl'erences  ])etween  the  i)upa  of  C'lilex  and  that  of  Anopheles.      In  this 
stage  the  insects  of  the  two  genera  an^  not  so  markedly  diflerent  as  in 
the  larval  stage.     Structural  dirfVrences  need  not  l)e  described,  as  the}'      ; 
are  sufliciently  shown  in   the  illustration.     The  (\ve  will  at  once  l3e      j 
caught  hy  the  diflerence  in  position,  the  pupa  of  Culex  resting  in  a      \ 
more  |)erpendicular  attitude  than  that  of  Anopheles,  and  the  marked 
difference  ifi  shape  between  the  respir.itory  siphons,  which  issue  from 
the  thorax  instead  of  from  the  anal  end  of  the  abdomen,  will  at  once 


41 

be  noticod.  Tho  pupa  of  Anopholos  is  quite  as  aotivo,  when  flistur))0(l, 
as  is  that  of  Culox.  If  one  toiiehes  the*  near-hy  surface  of  the  wattn' 
with  the  finger  the  pupa  at  once  wriggles  violently  away,  returning 
shortly  to  the  surface  for  air. 

The  duration  of  the  pupal  stage  in  An()phel(\s  varies  according  to  the 
weather.  Five  days  was  th(^  niininuun  ()])served  during  June,  although 
several  specimens  rtMuaincd  in  this  stagi*  for  ten  days.  The  adults  issue 
as  do  those  of  C'ulex. 

The  entire  life  round.  tluM'efore,  of  Anophdex  quddrimdmhifux  in 
the  generation  studied  by  the  writer  is  as  follows:  Vj^^^^  stage,  three 
days;  larval  stage,  sixteen  days;  pupal  stage,  five  days;  making  a  total 
period  in  the  early  stages  of  twenty-four  days.  It  should  be  stated, 
however,  that  during  the  early  larval  existence  toward  the  end  of  May 
there  occurred  nearly  a  Aveek  of  cool  weather,  so  that  it  is  certain  that 
in  the  hot  season  in  July  and  August  the  growth  and  transformations 
will  be  more  rapid.  It  w411  be  remembered  that  the  writer  traced 
Culex  pimgei}.^  through  an  entire  generation  in  the  latter  part  of  June, 
1895,  in  ten  days. 

NATURAL   BREEDING    PLACES   OF    ANOPHELES. 

Having  accomplished  the  preliminary  work  of  studying  different 
stages  of  growth  of  Anopheles  by  breeding  from  captured  females,  we 
were  enabled  to  become  familiar  with  the  larvae  and  pup^e  so  as  to 
recognize  them  readily  and  it  was  then  not  difficult  to  find  the  natural 
breeding  places.  The  first  breeding  place  discovered  was  in  Maryland, 
and  the  larvse  found  there  were  those  of  what  is  probably  A.  puncti- 
penni.^.  They  closely  resemble  the  corresponding  stage  of  A.  quad- 
rimaculaMis  except  in  the  maculation  of  the  head.  A  figure  of  the 
head  of  this  form  is  shown  here  (fig.  17)  in  order  that  it 
may  be  compared  with  the  corresponding  figure  of  A. 
quadrimaculatus  shown  in  fig.  15.  This  first  breeding 
place  of  Anopheles  was  a  small  permanent  stream  run- 
ning through  the  woods  which  had  here  and  there  ])road- 
ened  out  into  little  shallow\s.  and  in  these  shallows  the 
Anopheles  larvje  were  found  resting  at  the  surface  of  fig.  \i .—Anopheles 
the  water,  and  occasionallv  darting  from  one  spot  to      pnnctipennis: 

1  1-     i"  1  1  1         1  Head     of     full- 

another.    All  ot  these  little  pools  were  abundantly  sup-      grown lana from 
plied  with  alo'?e,  and  from  specimens  brought  in  Mr.      above— enlarged 

^  »     '  L  r^  (original). 

A.  F.  Woods  has  found  that  the}^  l)elong  to  the  genus 
Mougeotia.  There  were  also  many  Diatoms  present.  The  next  natural 
breeding  place  found  was  in  pools  about  a  disused  spring  in  Virginia. 
At  the  sides  of  the  spring  were  several  more  or  less  permanent  pools 
of  considerable  depth  (8  to  10  inches).  Here  the  larvjB  of  A.  quad- 
rhnaculatim  were  found.  Alga^  also  occurred  here  and  ]\Ir.  Woods  has 
determined  them  as  belonging  to  the  same  genus  Mougeotia.     The 


42  Ja. 

toiiijx'ratui'c  of  this  wator  was  Is^  C.  The  third  locality  was  an  old 
canal  IkhI  so  nrarlv  dried  out  after  a  season  of  drought  that  the  water 
lay  in  lather  small  puddl"s.  In  this  ease  the  water  was  ver\^  foul  and 
alj^a'  of  the  trenus  Lynj^^hya  were  pi'esent.  The  teni})eraturc  of  this 
watei-  was  *jr»  (\.  and  the  conditions  were  those  of  (^xtreuie  stajii^nation. 
The  tiisi  hxality  was  discoNcicd  hy  the  writer  in  company  with  Mr. 
Pratt  and  the  second  and  thiid  were  found  hy  Mr.  Piatt.  Later,  the 
wi'itei-  in  <<)in|)any  with  Mr.  Husck  and  Hospital  Steward  Smith,  found 
empt\  j)iipa  skins  of  .1.  «ji((ti/rtin(i<-uhifiis  in  a  di'ied  up  surface  pool  at 
the  \\'ashin<rton  Pairacks,  at  a  time  when  malaria  was  very  prevalent 
amon^::  the  troops.  I  am  informed  hy  Dr.  Thayer,  of  Baltimore,  that 
Dr.  Lazear  found  ,1.  jHi/irtij}rnnit<  })reeding  in  a  stone  quarry  near 
Baltimore,  in  the  suuunerof  181>1).  Ro.ss  found  in  India  that  while  the 
species  of  Culex  jjf(*nerally  hred  in  vessels  of  water  around  the  houses, 
the  species  of  tin*  ij^enus  Anopheles  hred  in  small  pools  of  water  on 
the  trroiind.  This  point  was  made  the  suhject  of  a  special  investiga- 
tion hy  the  e\])editi()n  of  the  Liverpool  School  of  Tropical  Medicine 
to  Siei-rti  Leone.  While  Culex  larva*  were  to  he  seen  in  almost  every 
vessel  of  water  or  emi)ty  gourd  or  flowei'pot  in  which  a  little  rain 
water  had  collected,  in  oidy  one  case  were  Anopheles  larva'  found  in 
.such  recei)tacles.  On  the  other  hand,  they  occurred  in  ahout  100 
small  })uddles  .scattered  throughout  the  cit}^  of  Freetown — puddles 
mostly  of  a  fairly  permanent  d(\<cription,  kept  tilled  hy  the  rain,  and 
not  liahle  to  washing  out  during  heavy  showers.  It  was  noticed  also 
that  the  larvai  seemed  chiefly  to  feed  on  green  water  weed. 

In  the  interesting  and  important  pap(M-  hy  Dr.  J.  W.  W.  Stephens 
and  Mr.  S.  K.  Christophers  entitled  "The  distribution  of  Anopheles 
in  Sierra  Leone,"  published  in  the  report  of  the  malarial  eonnnittee  of 
the  Royal  Society,  July  <>,  liHJO,  it  is  stated  that  at  Freetown  not 
only  do  the  larvie  of  Anopheles  exist  in  the  small  pools  in  the  rocks, 
but  also  in  the  pools  by  the  sides  of  streams  and  in  certain  small 
drains,  and  that  in  th(»  dry  season,  in  the  ab.sence  of  the  rock  pools, 
Anophides  breeds  freely  in  streams  and  drains;  also,  in  the  drv  season, 
the  adults  exist  in  mo.st  parts  of  the  town  in  dwellings,  especially  in 
overcrowded  native  huts  and  native  quarters,  ready  to  lay  their  eggs 
when  pools  appear.  It  is  inter(\sting  to  note,  from  this  latter  okser- 
vation,  that  the  authors  of  the  paper  recommend  the  destruction  of 
dirty  huts  and  the  prevention  of  excessive  overcrowding.  Outside  of 
the  city,  in  the  '*  luish,''  Anopheles  larviv  were  present  throughout  the 
whole  district.  In  the  mountain  streams,  wherever  there  were  suitable 
pools,  nudtitudes  of  larva^  existed.  In  tracing  the  mountain  .stream.s, 
occasionally  for  a  half  mile  or  so,  they  found  no  larva\  but  then  a 
rock  pool  occurred,  and  there  they  were  again  found  in  nund>ers.  At 
Songo  and  Mabang  they  were  able  to  detect  Anopheles  larvae  in  the 
swamps.     They  were  not  present  in  the  main  swamp  water  on  account 


43 

of  tho  innuin(M*5i])l(*  small  fish,  ])ut  wcm'c  occiisionsilly  ohscrvcd  in  sinall, 
isohitcd  [)()()ls  on  the  iniul,  and  wiM'c  still  more  common  in  small  pools 
at  the  ed^'os  of  swamps.  It  is  a  notcwoi-thv  fact  (hat  they  did  not 
occur  in  swam})  pools  in  such  mnnhcrs  as  in  the  streams  and  rock 
pools  amono-  thi^  hills  of  Sierra  Leone.  **  These  i-ock  pools  would 
appear  to  be  the  most  suitable  condilions  for  the  IncedinL;-  ot 
Anoph(des.'' 

The  avidity  with  which  Ano})holes  larvii?  under  observation  in 
Washington  fed  upon  algte  sporcvs  of  the  j^enera  previously  mentioned, 
and  the  chai'actiM'  of  the  breeding-  pools  found  here,  indicate  that  with- 
out doubt  snnilar  conditions  will  prevjiil  geneially  in  this  country,  and 
Anopheles  will  always  be  found  to  breed  most  abundantly  in  fairly 
permanent  stagnant  pools  of  water  uninhabited  by  tish,  but  more  or 
less  covered  with  green  scum. 

OTHER    SPECIES    OF    ANOPHELES. 

As  appears  from  the  synoptic  table  on  previous  pages,  we  hav.^  in 
the  United  States,  so  far  as  ascertained,  three  recognized  species  of 


Fig.  18. — Anopheles  punctipennis:     Female,  with  male  antenna  at 
right,  and  wing  tip  showing  venation  at  left — enlarged  (original). 

this  genus.     A.  quadrimaculatus  has  just  been  figured  in  all  its  stages, 
and  the  accompanj' ing  illustration  (fig.  18)  shows  very  well  the  beautiful 


44 


sjHM'irs  known  jis  A.  jtftnrf/'jtr/i/f/'s  Sjiy.      .1.  r/v/r/V/z/.v  (fi<r.  19)  sooms  to 
ln'iairj-  than  tlir  otlicr  two  and  has  hccMi  tnk«Mi  only  in  a  few  instances 


.  i<i.  \9.— 'Anopheles  rnicians:  Feraak- — i'nhirge<l  (original). 
DISTRIBl'TION    OF   THE   SPECIES    OF    ANOPHELES    IN    THE    UNITED   STATES. 

Anopheles  crucians  Wied. 

IIa])itat:  District  of  Coluiuhia,  Ajiril  27  (Pergande);  Georgia  (Nat.  Mus.);  New 
Orleans,  I^a.,  .Tuiie2S  (  Veazie),  NovemlHT (Thayer);  Rieluiiond,  Va.  (Sk>s.**on). 
Anopheles  inNrrn'ENNLs  Say. 

( (\)nsidere<l  hy  AViedcmaini  to  be  tlic  same  s}>e('it's  as  his  Aiwpheh','<  rrnrianj*,  Imt 

the  tw<)  are  certainly  <listinet.) 
Habitat:  Castleton,  Vt.,  February  1  (temperature  6°  F. );  Beverly,  Mass.,  Sep- 
tembi^r  19,  October  2;  Cambridge,  Mass.,  June  !(>,  September  80,  Octolx»r  20 
(Nat.  Mils.);  Charlton  Heights,  Md.,  March  81,  Novendx^r  17  (Pratt);  District 
of  Columbia.  June  (iand  7,  October  15,  2o,  and  81  (Pergande);  Philadelphia,  Pa., 
OctolH'r  12  (JohiLson);  Ithaca,  N.  V.,  April  17,  August  2S  (C\>mstock);  Illinois 
OctolH'r  1()  (Na.'^on);  Texiis  (Nat.  Mus.);  Mesilla,  N.  Mex.  (C<x'kerell);  Port- 
land, Jamaica  (.lohnson);  Middletown,  Conn.  (Davis);  Sunnnit,  N.  J.,  April  2() 
(Howard);  RoaiiokcVa.,  ()ctolx«r  (Thayer);  St.  Elmo, Va.,  May,  June  (Pratt); 
Brazos  River,  Tex.  (Woldert);  Baltimore  (Thayer  an<l  I^zear);  Walbrook, 
Md.  (Thayer  and  T^zear);  Onaga,  Kans.  (Crevecoeur). 
Anopheli-x  tirADKiMAciLATrs  Say. 

Habitat:  Berlin   Falls,  N.  H.,  August  (Nat.  Mus.);  Ithaca,  X.  Y.,  January,  July 
81,NovcndH'r28(Coiustock);  Lakeland,  Md.,  AugustH;  Charlton  Heights, Md., 


L 


45 

NovoiiiIk'  24  (Pratt);  District  of  ('oliiinhiii,  .Inly,  Octoln'r  15,  Novrrnln'r  L' iiiid 
14  (I\M«;aii(U');  Illinois,  St'ptriiilM'r  10,  Octohcr  i()(Nasoii);  St.  Anthony  Park, 
Minn.,  DociMnlu'r  II  (Ln<;^i'r);  Tick  Island,  Fla.,  May  12  (Johnson);  Texas 
(Nat.  Mus.);  Oneco,  Kla.,  May  2()  ((iossani);  Poan(>ki',  Va.,  October  (Thayer); 
Newport  News,  Va.,  October  (Tiiayer);  St.  Khno,  Va.,  Ai)ril,  May,  June,  July 
(Pratt);  New  Orleans  (Thayer);  Sparrows  Point,  M(l.,an(l  vicinity  (Thayer 
and  Lazear);  Middletown,  Conn.  (Davis). 

TIIK    (JKNUS    I'SOiiOlMIOKA. 

But  one  species,  P.  clllafu^  of  the  (^eiuis  Psorophorji  is  known  in 
the  Ignited  States.  This  is  Avell  iUustrated  in  the  {icconiiKinyiiijr 
figure  (hg.   20).     Although  this  insect,  as  indicated  in  the  synoptic 


Fig.  20. — Psorophora  ciliata:    Female — enlarged  (original). 

tables,  is  really  yellowish  in  color,  yet  the  general  effect  when  one 
glances  at  it,  or  sees  it  flying,  is  that  it  is  ver}^  dark,  almost  black. 
The  wings  are  not  really  spotted  or  infuscated,  but  the  very  numerous 
dark  scales  on  the  main  veins  make  the  wings  appear  dark.  They  are 
also  when  seen  in  certain  lights  prismatic  in  color  effect.  The  palpi 
of  the  female  are  nearly  half  as  long  as  the  beak,  and  the  beak  itself 


46 

is  vorv  stout.  Tho  most  striki?!*^  fcatiiro  of  this  insect,  however,  is 
the  ciirioiis  series  of  erect  close-set  hairs  or  scales  on  the  le^s.  which 
(listinjj^uishes  it  at  once  from  other  mosquitoes.  This  mosquito  is 
widespread  in  tlie  I'nited  States,  and  we  have  specimens  from  Dorches- 
ter, Mass.  (Nat.  Mus.);  Washinoton,  1).  C.  (Chittenden);  Westtield, 
N.  J..  July  :i  (Johnson);  Illinois  (Nason);  Brooklyn  Bridge,  Ky.,»Iune 
'J.S  ((rarman);  Lincohi,  Nelir.,  July  and  Aujifust  (Bruncr);  Los  Angeles, 
(  al.  (('(Kjuillett);  San  Diego.  Tex..  May  15  (Sihwarz);  Florida,  July 
(Nat.  Mus.);  Hastings,  Fla.,  July  (Dept.  Agric);  New  Orleans 
August,  (Veazie).     A  rather  large  series  was  captured  in  June  of  the 


Fig.  '21. — Megarhimis  riUilns:  Female— enlarged  (original), 

present  year  at  St.  Elmo,  Va.,  by  Mr.  Pratt.  The  writer  felt  certain 
that  he  would  be  able  to  follow  out  the  life  history  of  this  species  from 
the  living  material  captured  ])v  Mr.  Pratt.  Females  were  placed  alive 
in  })reeding  jars  under  conditions  which  had  repeatedly  been  successful 
with  Culex  and  Anopheles,  but  no  eggs  were  ol)tained.  The  breeding 
hal)its,  therefore,  may  })e  different  from  those  of  the  other  two  genera, 
and  the  biology  of  this  form  is  an  interesting  and  important  point  for 
future  investigation.  As  elsewhere  stated,  the  possible  relations 
between  Psorophora  and  the  I  lamiatamoebae  deserve  early  investigation. 


47 


THK    (J KNITS    MKGARHINIJS. 

This  is  the  other  oimhis  (ti<^.  21),  the  s])e('ies  of  which  ;ir<>  more  or 
less  {il)UiKliiiit  ill  the  South,  wiiich  slioiikl  l)e  iiivesti<i-5ite(l  hy  Southern 
observers  in  rej^ard  to  its  possihh*  eoniieetion  with  nmhiriii.  As  indi- 
cated in  the  synoptic  t4il)h\  the  nios(juitoes  of  this  ocmuis  ai'e  readily 
distinguished  l)y  the  curved  h(»ak.  wliich  is  also  well  shown  in  the  draw- 
ing*. Thi'v  are  especiall}^  distinguished  also  by  their  metallic  greenish 
or  bluish  coloration.  Nothing  is  known  of  the  life  history  of  the  mos- 
quitoes of  this  genus,  and  the  species  known  to  occur  in  this  country 
are  distributed  as  follows,  so  far  as  our  records  go: 

Megaktuncs  fekox  Wied. 

Habitat:  District  of  Colombia,   August  22    (Pergande);    (Georgia  according  to 
Walker's  list). 
Megarhixls  h^morrhoidalis  Fabr. 

Habitat:  (Cayenne  and  Cuba  according  to  Osten  Sacken's  catalogue). 
Megarhinus  portoricensis  Roeder. 

Habitat:  Benoit,  Miss.,  July  18  (Hine). 
Megarhinus  rutilus  Coq. 

Habitat:  North  Carolina;  Georgiana,  Fla.  (Nat.  Mus.). 


Fig.  22.— Aedes  sapphirinus:  Female— enlarged  (.original). 


THE    GENUS   AEDES. 


The  mosquitoes  of  this  genus  (fig.  22)  are  minute  forms,  insignificant 
in  color, and  the  only  one  of  which  we  possess  specimens,  viz.,  A.  sap- 
phirimcs,  is  shown  in  the  accompanying  figure.     We  have  received  it 


48 

only   from   Ithaca.  N.  V.,  llinmj^li  the  kiiidiu'ss  of   Prof.  ,1.  H.  Coin 
stock.      Another  spccii's,  . I. /'//>< //.s,  i^  said  by  Osteii  Sueken  to  occur 
at  Cauil)ridg'e,  Mass. 

THK    NATUKAL    KNEMIES    OF    MOSgUITOES. 

Tlir  late  l>r.  Kohcrt  II.  Laiiihorn,  of  New  York  and  Philadelphia, 
while  eno-at^^ed  a  nmnl)ei-  of  years  aj^o  in  huildin<r  the  I^ike  SiHK*rior 
and  Mississippi  Kadroad,  fell  in  with  a  jj^reat  many  mos(iuitoos.  He 
ofton,  ''with  a  sentiment  of  gratitude/'  as  he  expressed  it,  looked 
throujxh  his  mostjuito  veil  at  the  drat^on  Hies  which  collected  in  the 
open  spaces  among  the  pine  trees.  "They  darted  from  side  to  side, 
like  swallows  in  a  meadow,  but  with  amazing  rapidity,  and  at  every 
turn  a  moscpiito  'ceased  from  trou})ling.' "  This  gave  Dr.  Lam))orn 
the  idea  that  pi'rhaps  dragon  flies  might  be  domesticated  and  utilized 
to  destroy  mosipiitoes  along  the  New  Jersey  coast  and  elsewhere;  and 
so  he  ottered  prizes  for  the  three  best  essays  regarding  methods  of 
destroying  the  moscjuito  and  the  house  fly,  especially  designating  the 
dragon  fly  for  careful  investigation.  The  successful  essiiys — by  Mrs. 
C.  B.  Aaron,  Mr.  A.  C.  Weeks,  and  Mr.  William  BeutenmfUler — were 
pu))lished  ))y  Dr.  Lam])orn  in  a  volume  entitled  '' Dragon-Flies  v'«. 
^los(iuitoes.  The  Lamborn  prize  essays."  The  essays  were  all  excel- 
lent. Here,  howcNcr,  they  are  mentioned,  by  the  way,  in  connection 
with  the  group  of  the  best-known  natural  enemies  of  mos(|uitoes, 
namely,  the  dragon  flies.  It  is  needless  to  say  that  none  of  the  essa3'S 
were  able  to  solve  the  prolilem  of  a  practical  breeding,  on  a  large 
scale,  of  dragon  flies  for  mosijuito  extermination,  and,  in  fact,  the 
whole  subject  of  the  natural  enemies  of  the  mosquito  is  of  little 
practical  importance.  It  is  simply  a  matter  of  geneml  interest. 
Dragon  flies,  as  adults,  feed  upon  adult  mos(juitoes,  just  as  they  will 
upon  all  other  insects  which  they  are  able  to  capture  and  devour. 
Dragon  flies,  as  larva*,  feed  upon  the  larvte  and  pupa?  of  mosquitoes, 
although  other  and  larger  and  less  active  aquatic  insects  and  small  tish 
form  the  bulk  of  their  food. 

The  extreme  activity  of  both  larMc  and  pupie  of  mosquitoes  is  a 
necessary  factor  in  their  struggle  for  existence,  since  stagnant  pools 
of  water  fairly  swarm  with  predatory  animal  life.  The  larva  of  one 
of  the  water  l)eetles  of  the  family  Hydrophilidic  eats  hundreds  of 
other  insects  in  the  course  of  its  existence,  and  the  larvte  of  mos(iuitoes 
do  not  escape  entirely,  although  by  their  extreme  activity  they  stand 
a  }>etter  chance  than  do  other  more  sluggish  species.  A  small  pool  of 
watei-  on  the  Department  grounds  at  Washington  is  situated  near  a 
manure  ]/ile.  and  the  water  is  colored  dark  brown  by  the  dminage 
from  the  manure.  The  })ool  is  kept  ])y  Mr.  Saunders,  the  superin- 
tendent of  the  grounds,  for  tiie  i)urpose  of  securing  manure  water 
for  some  of    his   plants.     It  is,   at  all   times  through  the  suiumer, 


49 

swarm iiij,'-  witli  tUv  lar\ii'  of  ('t(/r,r  jniini,its^  ('.  stiiin(/ans^  and  ('.  per- 
turh<Uif<;  also  with  tlir  larva  of  an  Kphydrid  lintr/u/ilrittmi  tinjr/ifdfa 
Walk. — and  with  the  larva  of  an  Kplicincrid  of  the  j^fcniis  Ctiinis,  and 
other  a(iuatic'  species.  A  niunber  of  s})eeiniens  of  IIydi()])hilid  lar\  a' 
were  found  by  the  writer  in  this  pool.  They  fed  \\\)n\\  the  other 
aquatic  insects  with  axidity,  and  three  of  them  were  phiced  in  a  lai^^c 
battery  jar  with  a))()ut  a  half  gallon  of  this  water,  teemino-  with  insect 
life  and  containing-  apparently  some  hundreds  of  tlie  moscjuito  larvie 
and  many  of  the  others  just  mentioned.  Th(\sc  three  Hydrophilid 
larva\  in  the  course  of  ,a  week,  practically  devoured  all  of  the  other 
animal  life  in  the  jar.  Only  tw^o  male  mos(iuitoes  and  one  female  suc- 
ceeded in  reaching  the  adult  stage. 

No  one  can  realize  the  intensity  of  the  struggle  for  existence  which 
is  going  on  in  a  stagnant  pool  until  he  forces  himself  to  the  seemingly 
rather  unpleasant  occupation  of  l3"ing  down  by  its  side  and  watching 
with  a  large  hand  lens  the  various  forms  of  life  with  which  the  water 
is  swarming.  Aside  from  the  larva;  of  the  dragon  flies  and  the  preda- 
tory larvce  of  the  three  great  families  of  aquatic  beetles,  namely,  the 
Dytiscidai,  the  Hydrophilida^,  and  the  Gyrinidte,  there  are  aquatic 
neuropteroid  insects  which  are  predatorv  and  which  feed  upon 
mosquito  larva?  as  well  as  others,  like  those  of  the  genus  H^dro- 
ps3xhe;  and  there  are  aquatic  Heteroptera  which  are  also  predatory. 

Aside  from  insects,  there  are  many  other  natural  enemies  of  mosqui- 
toes. Many  fish  eat  their  larva?  and  pupae,  and  such  night-flying  birds 
as  nighthawks  and  whip-poor-wills,  and  bats  as  well,  destro}'  the  adults. 
Harve}^  (American  Naturalist,  1880,  p.  896),  quoted  by  Mrs.  Aaron, 
found  600  mosquitoes  in  the  crop  of  a  nighthawk. 

REMEDIES   AGAINST   MOSQUITOES. 

Remedies  in  houses  and  the  prevention  ofhites. — Of  the  remedies  in 
use  in  houses  the  burning  of  pyrethrum  pow^der  and  the  catching  of 
mosquitoes  on  the  walls  in  kerosene  cups  are  probabl}'  the  best,  next 
to  a  thorough  screening  and  mosquito  bars  about  the  bed.  In  burning 
P3^rethrum  powder  it  is  well  to  moisten  the  powder  sufficiently  with 
water  so  that  it  can  be  molded  roughW  into  little  cones  about  the  size 
of  a  chocolate  drop.  These  cones  are  placed  on  a  pan  and  dried  in 
the  oven.  If  ignited  at  the  apex  the  cones  smolder  slowly,  giving  off 
an  odor  not  unlike  that  of  the  prepared  punk  which  bo3^s  in  this 
country  use  to  light  firecrackers.  Two  or  three  of  these  cones  burned 
in  a  room  in  the  evening  will  give  relief  b3^  stupef34ng  the  mosquitoes. 
This  smoke  appears  to  be  perfectl3"  innocuous  to  human  beings.  The 
writer  has  breathed  it  evening  after  evening  without  the  slightest  per- 
ceptible ill  effect.  The  method  of  catching  mosquitoes  on  the  walls 
with  kerosene  in  cups  is  now  in  frequent  use  in  different  parts  of  the 
3949 i 


50 

fomitrv.  No  one  srcins  to  know  who  invciiti'd  it.  ])ut  the  writfi*  tir>;t 
saw  it  ill  oiuTation  some  vrars  a«:fo  in  N«'w  Jersey,  and  was  struck  with 
its  siiii}>licity  and  ctlicacv.  The  top  of  a  tin  ))aki!ig-powd(M'  l»ox  is 
iiiNcrtrd  ar.d  naih'd  to  the  t'lid  of  a  stick  of  yullicicFit  h'lijrth  to  reach 
to  tlic  ccilini:.  A  small  <|iiantity  of  kerosene  is  jmt  into  this  inipro 
vised  cup  aiul  the  a[)pa!atus  is  puslied  up  undci-  restinif  iiiostjuitoes. 
which  fall  into  tlie  kerosene  and  ar«*  (h'sti'oyed.  It  is  the  custom  in 
certain  iiouses  to  systematically  hunt  for  iiiosijuitoes  in  the  bedrooms 
with  such  an  ap[)aratus  every  ni^'^ht  hefore  reiirinj,'". 

Camphor  ruhhed  on  the  face  and  hands  or  a  few  drops  upon  the 
pillow  at  ni^rht  will  kei'p  iiios((uitoes  away  foi*  a  time,  and  this  is  also 
a  well-known  jirojx'rty  of  oil  of  pennyroyal.  The  use  of  oil  of  pepper- 
mint, lemon  juice,  and  vinej^ar  have  all  been  recommended  as  jiro- 
tectoi-s  aufainst  nioscpiitoes,  whiiv'  oil  of  tiir  jis  used  against  the  hlack 
tly  in  Canada  is  also  used  in  ])ad  inos(piito  localities.  Strong-ly  cam 
phorated  \aseline.  althoutj^h  recommended,  has  been  found  by  Dr. 
Nuttall  to  be  of  scarcely  any  use  in  Canada. 

One  of  the  London  papers,  the  Daily  Telegraph,  invited  its  readers 
to  send  in  moscjuito  remedies  of  this  kind  during  the  summer  of  1899, 
and  some  of  the  substances  recommended  were  as  follows: 

FAicalyptol  on  the  ykin,  with  a  handkerchief  saturated  with  it  plact^l  on  tlie  jiillow 
at  night — the  result  of  South  African  experience.     (Arthur  E.  PMwards. ) 

Carbolated  va.seline.     (Dr.  Geoi-ge  Mackern.)  a 

One  drop  of  oil  of  lavender  on  pillow,  and  one  (^n  the  licad  at  night.     (A.  E.  S, ) 

Tincture  of  Ltd'j'm  ^>oZ«-s/r.r.     (M.  Fisher.) 

Piece  of  cotton  wool  soaked  in  oil  of  ch»ves  on  each  side  of  the  lied  curtains. 
(W.  B.) 

Anoint  skin  with  o  parts  relined  paraffin  and  I  part  crushe*!  canii)hor.  (\V.  T. 
Catleugh.) 

To  heal  the  bite«,  a  drop  of  iitpiid  ammonia.     (P.  G.  L.) 

Eucalyptus  oil.     (X.) 

Same  substance.     (Dr.  George  Gohen.) 

Oil  of  eucalyptus  and  creosote,  each  5  drops,  to  l>e  thoroughly  mixe<l  with  I  ounce 
of  glycerin.     (R.  R.  P.  S.  Bowker.) 

Place  a  line,  juicy,  uncooked  l)eefsteak  near  the  l>ed  on  retiring.     (M.  M.  M.) 

A  substance  with  which  the  writer  is  not  familiar,  but  which  is 
spoken  of  very  highly  in  the  interesting  paper  by  the  Italians  Celli 
;ind  Casagrandi  in  a  paper  to  which  we  shall  have  occasion  to  refer 
later  in  speaking  of  remedies  against  the  larva,  is  a  yellow  aniline  color, 
referred  to  in  the  work  of  the  Italians  a^  Larycith  III.  They  state 
that  a  little  of  this  substance  burned  will  kill  the  adult  mosquitoes 
and  that  this  method  constitutes  the  most  efficacious  means  of  destroy- 
ing them.  The  Chinese  use  pine  or  juniper  sawdust,  mixed  with  a 
small  (piantity  of  brimstone  and  1  ounce  of  arsenic,  run  into  slender 
bags  in  a  dry  state.  Each  bag  is  coiled  like  a  snake,  and  tied  with 
thread.  The  outer  end  is  lighted.  Two  coils  are  said  to  be  sufficient 
for  an  ordinarv  room,  and  lOU  coils  sell  for  G  cent^. 


51 

Rmirt/iis  fur  h/fts.  Dr.  K.  O.  Pctk.  of  Mdiiislown,  N.  J..  \n  lotc 
to  tliis  otlicc  hist  smnnuT  stji(in«:-  tlint  he  had  found  l:1\ cciin  a  -onci- 
eit^n  I'urc  for  tin*  l)it('s.  Touch  I  he  l)it«'  with  olvccriii.  and  in  a  few 
niimitos  tlio  i)aln  is  vroxw.  According-  to  I)r.  Peek  it  also  took  the 
pain  from  Ihm'  stiniis.  Dr.  C'harh's  A.  Nash,  of  New  York  City,  has 
roiHMitly  inforiiKHl  the  writer,  \^\  corrcspondcnri'.  thai  whcnrNcr  a 
iiiosquito  ])itos  liini  \\v  rubs  tiu'  spot  and  marks  it  with  a  hunj)  of 
indioo.  This,  ho  says,  "instuntiuu'ously  renders  the  bite  absohitel}^ 
of  no  aecount,''  whether  the  application  is  made  immediately,  the  next 
day.  or  the  day  after.  He  has  used  it  since  1878,  and  lives  in  a  New 
Jersey  town  where,  lie  writes,  •*mos(]uitoes  are  a  pest  every  3- ear." 
He  finds  the  same  application  to  g'ive  relief  from  the  stings  of  the 
yellow  jacket.  Household  ammonia  has  ])een  found  b^^  man}'  persons 
to  give  relief. 

DESTKUCTION    OF    LAKV^    AND    ABOLITION    OF    BREEDING    PLACP:S. 

The  following  paragraphs  are  quoted  from  the  writer's  article  in 
Bulletin  No.  1: 

"Altogether  the  most  satisfactory  ways  of  lighting  mosquitoes  are 
those  which  result  in  the  destruction  of  the  larva?  or  the  abolition  of 
their  breeding  places.  In  not  every  locality  are  these  measures  feasi- 
ble, ])ut  in  many  places  there  is  absoluteh^  no  necessity'  for  the 
mosquito  annoyance.  The  three  main  preventive  measures  are  the 
draining  of  breeding  places,  the  introduction  of  small  tish  into  fishless 
breeding  places,  and  the  treatment  of  such  pools  with  kerosene. 
These  are  three  alternatives,  any  one  of  which  will  be  efficacious,  and 
any  one  of  which  may  be  used  where  there  are  reasons  against  the 
trial  of  the  others. 

^''Kerosene  on  hreeding 2^ools. — In  1892  the  writer  pul^lished  the  tirst 
account  of  extensive  out-of-doors  experiments  to  determine  the  actual 
effect  upon  the  mosquitoes  of  a  thin  hner  of  kerosene  upon  the  sur- 
face of  water  in  breeding  pools  and  the  relative  amount  to  be  used. 
He  showed  the  quantit}'  of  kerosene  necessar}'  for  a  given  water  sur- 
face, and  demonstrated  further  that  not  only  are  the  larva?  and  pupee 
thereby  destroyed  almost  immediately,  but  that  the  female  mosquitoes 
are  not  deterred  from  attempting  to  oviposit  upon  the  surface  of  the 
water,  and  that  the}'  are  thus  destroyed  in  large  numbers  he/ore  their 
eggs  are  laid.  He  also  showed  approximately  the  length  of  time  for 
which  one  such  treatment  would  remain  operative.  No  originality 
was  claimed  for  the  suggestion,  but  only  for  the  more  or  less  exact 
experimentation.  The  writer,  himself,  as  early  as  186T,  had  found 
that  kerosene  would  kill  mosquito  larv»,  and  the  same  knowledge  was 
probably  put  in  practice,  although  without  publicity,  in  other  parts  of 
the  country.     In  fact,  Mr.  H.  E.  Weed  states  (Insect  Life,  Vol.  VH, 


52 

p.  'Ji'J)  tliat  ill  the  FiMMirli  (jiiaitci-  of  New  Orleans  it  has  Ihmmi  a  coiii- 
inoii  inacticc  for  many  years  to  phu*'  keroseiic  in  tlio  watiT  tanks  to 
K'sscn  tin-  nunilM  r<  of  inostjuitocs  in  a  jrivrn  locality,  although  he  knew 
n()thin«r  that  had  hi'cn  written  to  show  that  such  was  the  eiLse,  and  he 
says:  'In  thisa«i^e  of  ad\  anci-nient  we  can  no  lonj^er  tr<>  by  hearsay  evi- 
dence.' Suj^gestions  as  to  the  use  of  kerosene,  and  even  experiiiient.s on 
a  water  surface  lO  inches  sc(uai«'.  showin<r  that  the  lai'\  le  could  ))e  killed 
}>y  kiMosene,  were  recorded  by  Mis.  ('.  H,  Aaron  in  her  LanilK)rn 
prize  essay  and  published  in  the  work  entitled  "  Draj^on  Flies  tyersus 
Mosijuitoes'  (D.  Appleton  c<:  (\>.,  1M>0).  Mi-.  W.  Beuteninuller.  also 
in  tile  same  work.  ina(U>  tin-  same  su<rK^'-^tion. 

••'riic  (plant ity  of  kerosene  to  })e  practically  used,  as  shown  by  the 
writ<'r's  experiments,  is  approximately  1  ounce  to  ir>  xpiare  feet  of 
wat*'r  surface,  and  ordinarily  the  api)lication  need  not  be  renewed  for 
one  month.  Since  iSDri  several  demonstrations,  on  ))oth  a  large  and  a 
small  scab',  have  been  made.  Two  localities  were  rid  of  the  moscjuito 
plague  under  the  supervision  of  the  writer  hy  the  use  of  kerosene 
alone.  Mr.  Weed,  in  the  article  above  mentioned,  states  that  he  rid 
the  college  campus  of  the  Mississippi  Agricultural  College  of  mos- 
ipiitoes  })y  the  treatment  with  kerosene  of  eleven  large  water  tanks. 
Dr.  John  B.  Smith  has  recorded,  though  without  deUiils,  success  with 
this  remedy  in  two  cases  on  Long  Island  (Insect  Life.  Vol.  VI,  p.  91). 
Prof.  .1.  II.  (omstock  tells  the  writer  that  a  similar  series  of  experi- 
ments, with  perfectly  satisfactory  results,  was  carried  out  by  Mr.  Ver- 
non L.  Kellogg  on  the  campus  of  Stanford  Universit}',  at  Palo  Alto, 
C'al.  In  this  case  post  holes  filled  with  surface  water  were  treated, 
with  the  result  that  the  moscpiito  plague  was  almost  immediately 
alleviated. 

''Additional  experiments  on  a  somewhat  larger  scab-  have  been  made 
by  Rev.  ,Tohn  D.  Long  at  Oak  Island  Beach.  Long  Island  Sound,  and 
by  ^Ir.  W.  K.  Ilopson,  near  Bridgeport.  Conn.,  also  on  the  shores  of 
Long  Island  Sound,  the  experiments  in  both  cases  indicating  the  effi- 
cacy of  the  remedy  when  applied  intelligently.  I  have  not  been  able 
to  learn  the  details  of  Mr.  Hopson's  operations,  but  am  told  that  they 
included  extensive  draining  as  well  as  the  use  of  kerosene. 

"It  is  not,  however,  the  great  sea  marshes  along  the  coast,  where 
mos(piitoes  breed  in  countless  numbers,  which  we  can  expect  to  treat 
by  this  method,  but  the  inkuid  places,  where  the  moscpiito  supply  is 
derived  from  comparatively  small  swamps  and  circumscribed  pools. 
In  most  localities  people  endure  the  toiinent  or  direct  their  remedies 
against  the  adult  insect  only,  without  the  slightest  attempt  to  investi- 
gate the  source  of  the  supply,  when  tin*  \ cry  first  stej)  should  be  the 
undertiiking  of  .such  an  investigation.  In  '(ileanings  in  Bee  Culture' 
(Octo})er  1.  ISDo)  we  notice  the  statement  in  the  California  column 
that  in  some  California  towns  the  pit  or  vault  behind  water-closets  is 


58 

subject  to  flusliiiiy- Nvitli  water  (Imiiii^- llir  ii-rinat  ion  of  llicland  near!)}'. 
A  period  of  s(>veral  wet'ks  elapses  before  more  water  is  luiiied  in,  and 
in  the  meantinu*  the  water  hcconies  stagnant  and  the  hreedin*;'  phiee  of 
millions  of  nios(piitoes.  'Piien.  as  llie  cori-espondent.  says,  'people.  oQ 
around  wondcrino-  where  all  the  inos([uitoes  come  from,  put  u])  screens, 
biirn  ])uhach,  and  mak(*  a  oivat  fuss.'  Nothing  could  ])e  easier  than  to 
pour  an  ounce  of  kerost^ie  into  eacli  of  these  pits,  and  all  danger  fiom 
mos(piitoes  will  ha\'e  passed. 

"In  many  houses  in  Baltimore,  ^Fd..  the  sewage  drains  lirst,  into 
W'Clls  or  sinks  in  the  hack  yard,  and  thence  in  some  cases  into  sewers, 
and  in  other  cases  is  pumped  out  periodically.  Thes«^  wells  invariabl}^ 
have  open  privies  built  over  th(-m,  and  the  moscpiitoes,  Avhich  ])reed  in 
the  stagnant  contents  of  the  sinks,  have  free  egress  into  the  open  air 
back  of  the  houses.  Hence  parts  of  Baltimore  much  farther  removed 
from  either  running  or  stagnant  water  than  certain  parts  of  Washing- 
ton, where  no  mosquitoes  are  found,  are  terribly  mos(|uito  riddcMi,  and 
sleep  without  mosquito  bars  is,  from  May  to  December,  almost  impos- 
sible. Specimens  of  Ciilex  2yii'n{/(nx  captured  November  5  in  such  a 
privy  as  described  have  been  brought  to  the  writer  from  Baltimore  b}^ 
one  of  his  assistants,  ]Mr.  E.  M.  Reese. 

"Kerosene  has  been  tried  ])y  Mr.  Reese  in  one  case  in  Baltimore, 
and  two  treatments  of  a  privy  made  about  May  1  and  June  1,  respec- 
tiveh^,  seemed  to  diminish  the  numbers  of  the  pest  in  that  particular 
house;  but  without  concerted  action  of  all  the  householders  in  a  given 
block  (all  the  houses,  be  it  remembered,  being  exactly  alike  in  the 
method  of  sewage  disposal)  no  great  amount  of  good  could  be  accom- 
plished. With  such  concerted  action,  however,  there  seems  to  be  no 
reason  why  the  mosquito  plague  could  not  be  greatly  diminished  in 
man}",  if  not  most,  parts  of  Baltimore  at  a  very  small  expense.  Usualh' 
one  well  serves  two  houses,  the  privies  being  built  in  paii-s.  so  that  one 
treatment  would  suffice  for  two  dwellings. 

On  ponds  of  any  size  the  quickest  and  most  perfect  method  of  form- 
ing a  film  of  kerosene  will  be  to  spray  the  oil  over  the  surface  of  the 
water. 

''''Drainage. — The  remedy  which  depends  upon  draining  T)reeding 
places  needs  no  extended  discussion.  Naturally  the  draining  otl'  of  the 
water  of  pools  will  prevent  mosquitoes  from  breeding  there,  and  the 
possibility  of  such  draining  and  the  means  by  Avhich  it  may  ])e  done  wdll 
vary  wdth  each  individual  case.  The  writer  is  informed  that  an  elabo- 
rate bit  of  work  which  has  been  done  at  Virginia  Beach  bears  on  this 
method.  Behind  the  hotels  at  this  place,  the  hotels  themselves  front- 
ing upon  the  beach,  was  a  large  fresh -water  lake,  which,  Avith  its 
adjoining  swamps,  was  a  source  of  mosquito  supply,  and  it  was  further 
feared  that  it  made  the  neighborhood  malarious.  Two  canals  w^ere  cut 
from  the  lake  to  the  ocean,  and  bv  means  of  machinerv  the  water  of  the 


54 

hiko  wiu<  cliaii^j'd  from  ji  IkkIv  of  fresh  ton  Ixxly  of  suit  wjitc/.  Water 
that  is  soiiu'wlijii  hrackisli  will  support  inosijuitoes,  but  water  wliich 
is  purely  salt  will  destroy  tlieiu. 

"  I  Practical  ti.sc  (tfjiah. — Thci  introduetion  of  tisli  intofishless  breeding 
]>laces  is  aiiothei-  inatti'r.  Tt  may  be  undesirable  to  treat  eertain 
breediiiL!  pliices  with  kerosene,  as.  for  instiuiee.  water  which  is  intended 
lor  drinkinji".  althouich  this  has  becMi  don<'  without  harm  in  tunks 
where,  as  is  eushmiary,  the  drinking  supply  is  drawn  from  the  botU)in 
of  the  tank.  All  interesting  eas«'  not«'d  in  Insect  Life  (Vol.  IV, 
p.  1^2'i).  ill  w  liieli  a  })air  of  carp  was  })lace([  in  «'ach  of  several  tanks, 
ill  tli«'  Ki\  ieia.  is  a  cjisi»  in  point.  The  value  of  most  small  tishes  for 
the  purpos<»  of  destroying  mosipiito  lai'vie  was  well  indicated  by  an 
t'xperience  desciibed  to  us  by  Mr.  (\  IT.  Russell,  of  Bridgepcn't,  Conn. 
In  this  case  a  very  high  tide  broke  away  a  dike  and  flooded  the  salt 
meadows  of  Stratford,  a  small  town  a  few  miles  from  Bridgeport. 
The  receding  tide  left  two  small  lakes,  nearly  side  by  side  and  of  the 
same  size.  In  one  lake  the  tide  left  a  dozen  or  more  small  tishes, 
while  the  other  was  tishless.  An  examination  by  ^Mr.  Kusscdl  in  the 
summer  of  ISl>i  show(Ml  that  while  the  tishless  lake  contuinecl  tens  of 
thousands  of  mos(juito  lai'Vie,  that  containing  the.tish  had  no  lar\;e. 

"  The  us«M)f  carp  for  this  purpose  hjis  been  mentioned  in  the  pn'ceding 
paragraph,  but  most  small  lish  will  answer  as  well.  The  writer  knows 
of  none  that  will  Im^  better  than  either  of  the  conunon  little  stiekle- 
1)acks  ((r{f.sfr/'(f.sfrtfs  (iruhatu-s  ov  Pi/(j<>sfci(s  jHUKj if i u.s) .  They  are  small, 
but  very  active  and  very  voracious.  Mr.  F.  W.  Urich,  of  Trinidad, 
has  written  us  that  there  is  a  little  cyprinoid  common  in  that  island 
which  answers  admirably  for  this  purpose.  This  tisli  has  not  been 
specitically  determined,  but  we  hope  to  make  an  eti'ort  to  introduce  it 
into  our  Southern  Stfites,  if  it  proves  to  be  new  to  our  fauna.  At  Bee- 
ville.  Tex.,  a  little  fish  is  used  for  this  purpose,  which  is  there  called  a 
perch,  although  we  have  not  been  aide  to  tind  out  just  what  the  species 
is.  They  soon  <nit  up  the  mosquito  larva\  however,  and  in  order  to 
keep  them  alive  th<»-  people  adopt  an  ingenious  flytnip,  which  they  keep 
in  their  houses  and  in  which  about  a  (piart  of  Hies  a  day  is  caught. 
These  Hies  are  then  fed  to  the  lish.  This  makes  a  little  circle  whieh 
strikes  us  as  particularly  ingenious  and  ph^isant.  The  Hytraps  cat^di 
the  flies  and  rid  tln^  house  of  that  pest.  The  flies  are  fed  to  the  lish  in 
tIk*  water  tanks  and  keep  tlwin  alive  in  order  that  they  may  feed  on 
the  nios(|uito  lar\  ic.  thus  keeping  the  houses  free  of  moscpiitoes. 

"  Arl[p('t<d  (Kiiftifton  of  tJir  irdirr. — Where  kero.sene  is  considered 
objectiona]»le,  and  where  fish  can  not  be  readily  obtained,  there  is 
another  c(»iirse  left  op<'n.  It  is  the  constiint  artificial  agitjition  of  the 
water,  since  mosiiuitoes  will  oviposit  only  in  still  watei-.  At  San 
Diego,  Tex.,  in  the  suitumM*  there  are  no  streams  for  many  miles,  but 
plenty  of  moscjuitoes  l»reed   in   \\w  water   tanks.      Some  enterprising 


55 

individuals  kopt  thoir  tanks  U-rv  hy  putliiiLj-  in  a  lilth'  wIhm'I,  which  is 
turned  ))y  the  wiiuhnill.  and  U('«'})s  (he  watn-  ahnosl  constjintly 
ag-itated." 

Later  (it<e  of  I'erosenc. — Since  the  })u])Iicati()n  of  the  reconunc'ndations 
just  quoted,  a  great  deal  of  experimental  work  has  heen  carried  on  in 
ditt'erent  parts  of  tlie  country,  l)()th  on  a  small  scale  and  on  hirge 
scahvs.  An  unfortunate  editorial  note  published  in  the  vVmerican 
Naturalist  in  ISi);')  states  that  tlu^  writcM-  discovered  the  kerosene  treat- 
ment aoainst  moscjuito  larva',  whereas  in  liis  first  article  on  the  .sub- 
ject (Insect  Life,  Vol.  V,  pp.  VI  to  14)  he  ])eg{iii  with  th(^  ^vords:  "One 
of  the  most  reasonable  of  the  reeonuuendations  w  hich  have  been  made 
from  time  to  time  *  '"  '^'  is  the  application  of  kerosene  to  restricted 
and  fishless  breeding  ponds.''  The  note  in  the  Naturalist  was  the  text, 
however,  for  a  sarcastic  note  in  the  Revue  Scientifique,  1895,  Volume 
IV,  page  729,  by  a  writer  named  Delbceuf ,  aimed  not  onh^  against  the 
writer,  but  against  Americans  in  general.  He  stated  that  he  had  used 
kerosene  as  a  remedy  for  full}'  fifty  3  ears,  and  that  its  use  is  referred 
to  in  the  Journal  Pittoresque  for  184T,  page  80,  where  it  is  spoken  of 
as  something  already  well  known.  Since  the  writer  made  no  claims 
to  an}^  originality,  but  simph^  announced  exact  experimentation  upon 
a  somewhat  large  scale,  the  matter  may  rest  very  comfortably  where 
it  is.  But  it  is  interesting  to  note  here  that  as  long  ago  as  1812,  in  a 
work  published  in  London  under  the  title  "Omniana  or  Horse  Otio- 
siores,"  a  collection  of  odds  and  ends  of  all  kinds,  the  following  sugges- 
tion is  made: 

The  mosquito,  which  is  of  all  the  race  of  flies  the  most  noxious,  breeds  in  the 
water.  Might  it  not  be  jjossible  at  the  seasons  when  they  emerge  and  when  they 
deposit  their  eggs  upon  the  surface  to  diminish  their  numbers  by  pouring  oil  upon 
great  standing  water  and  large  rivers  in  those  places  which  are  most  infested  by 
them? 

The  writer  is  indebted  to  Mr.  D.  C.  Clark,  of  Baltimore,  for  this 
interesting  reference. 

During  the  past  few  3^ears  kerosene  has  been  rather  extensiveh'  used 
at  man}^  places  in  an  effort  to  limit  the  mosquito  supplv.  As  already 
pointed  out,  there  are  many  places  where  the  source  of  mosquito  sup- 
ply is  definitely  limited  and  eas}^  of  treatment,  and  in  such  cases  on 
account  of  the  cheapness  of  kerosene  it  will  be  the  best  means  of  erad- 
ication. In  other  places  where  communities  are  surrounded  with 
swamp  land  or  in  the  case  of  extensive  sea  marshes  kerosene  can  be 
practically  used  in  connection  w^ith  other  and  more  elaborate  measures, 
comprehending,  as  a  rule,  d\^king  and  draining.  At  a  relatively  slight 
expense,  however,  a  countr}^  club  on  Staten  Island  has  during  one  sea- 
son practically  stopped  the  breeding  of  Culex  ])imgei}ii  in  ponds  and 
marshes  in  the  vicinity  b}^  the  use  of  kerosene  alone.  This  substance 
has  also  been  used  with  good  effect  by  the  Town  Improvement  Society 


56 

:it  Summit,  N.  J.,  in  woodland  pools  and  swamp  land,  and  its  use  on  a 
Uivgv  s<ah'  is  )M*in<;  attcmpt^'d  thr  })n'S('nt  y«*ai'  in  the  vicinity  of  a  arge 
town  on  Long  Island.  Dr.  A.  I>.  Ho})kins,  of  Morgantown,  W.  V^a., 
tolls  tho  writci-  that  a)K)ut  ten  years  ago  an  exteiLsive  pumping  station 
was  located  near  the  river  Iwink  where  the  oil  pipo  line  crosses  a  mile 
above  Morgantown  and  that  the  oil  frecpiently  escapes  out  over  the 
river.  Since  tliat  time  the  city  has  ))cen  almost  exempt  from 
mosquitoes. 

In  ls:»T.  Mr.  .M.  .1.  Wightman,  while  interested  in  developing  a  new 
resort  known  as  Midland  Reach,  had  4  barrels  of  crude  |M*troleum 
scatt^Ted  over  the  marshes  surrounding  the  ]>each.  Foi*  three  weeks 
})re\  ioiLsly  tln'  mos(|uitoes  had  ])een  unl)earal)le.  The  employees  at 
the  ))«nich  went  aljout  witli  their  heads  covered  with  netting,  and  o^ 
couise  this  had  a  very  discouraging  influence  upon  visitors.  The 
oiled  district  cover(Hl  a  radius  of  lialf  a  mile,  and  Mr.  Wightman,  writ- 
ing in  1899,  stated  lliat  within  tiiree  days  after  the  oil  was  di.stributed 
mo.s(juitoes  were  rare  along  the  ))each.  This  condition  lasted  through- 
out the  season.  Recently,  owing  to  a  change  of  management,  the 
writer  is  informed  that  nothing  has  been  done  and  that  mosquitoes 
ha\'e  l)ecome  plentiful  again. 

Dr.  St.  (leorge  (Jray,  of  St.  Lucia,  Britisli  West  Indies,  writes,  after 
reading  Bulletin  -I  of  this  office,  that  he  has  tried  kerosene  in  his  well 
and  in  the  water  jars  in  his  yard  with  the  result  that  one  species  has 
disappeared  from  his  house  and  that  the  other  mo.squitoes  give  liim 
very  little  trouble. 

The  remedial  experiments  against  mosquito  larva^  tried  by  Doctors 
Stephens  and  Christopher  at  Sierra  Leone  are  given  in  the  reports  to 
the  malaria  conuuittee  of  th(^  Royal  Society,  London.  July  0,  19(X). 
The}'  selected  as  the  most  practical  larvicides  kerosene  (paraffin  oil) 
and  salt.  The  salt,  requiring  a  very  strong  solution,  was  not  experi- 
mented with  extensively.  A  few  handfuls  thrown  into  pools  contain- 
ing not  more  than  3  or  4  pints  of  water  produced  no  effect  in  three 
days.  With  kenxsene  the  rook  pools  and  small  runnells  of  water  were 
treated:  **The  larvicidal  etiect  in  the  pools  was  very  striking,  most  of 
the  lan^iv  being  killed  in  fifteen  minutes  or  less.  In  many  cases  again, 
besides  the  larvicidal  effect,  adult  females  were  found  next  day  killed 
by  the  paraffin  on  the  surface  of  the  pool  where  they  had  come. to  la}' 
their  eggs.-'  Thus  the  writer's  1893  olxservation  on  the  non-deterrent 
etiect  of  the  kerosene  film  on  adult  moscjuiti^xs  and  their  resultant 
destruction  befoi(»  the  eggs  are  laid  is  confirmed.  This  has  always 
.seemed  to  be  a  point  of  great  pi*actical  value  in  the  use  of  kerosene. 
Th<»  final  result  by  tli«^  English  observers,  however,  was  found  to  be  the 
immediate  i-etuin  of  the  ins(M*ts  on  the  cessation  of  thi^  application  of 
petroleum.  An  interesting  test  experiuKMit  was  made  by  them  ujwn  a 
surfa«e  drain  arising  from  a  s])ring  and  rumiing  for  3(K)  yards  when  it 


57 

ontored  a  ])rook.  Thosprinjjf  was  free  t'loin  I:ii\a  .  !>iit  thcdniin  Iccmcd 
with  tbeiii  throuohoiit  its  (Mitirii  length.  ()\rr  (liis  drain  kci-oscnc  oil 
was  spriidvUnl  ])y  incaiis  of  a  watoriii^-  ])()t.  About  4:  <»allons  siilliccd  to 
cover  the  drain  tliiekly  Avitli  oil.  '•'riic  ]ar\  icidal  eliect  was  imme- 
diate, and  on  the  foUowinif"  day  no  li\inu-  lar\  je  were  se(»n.  I'our  days 
later  traees  of  oil  were  still  i)res(Mit  in  places.  Ki^lit  days  later  small 
larvae  were  present  along  the  whole  drain.  "  *  *  A  weekly  a})i)li- 
cation  of  paraffin  then  would  eflectually  ])re^•(Mlt  the  foi-niation  of  the 
})erfeet  insect  in  tliese  situations." 

The  rapid  disappearance  of  the  kerosene  covering  in  this  hist  expcn-i- 
ment  is  quite  contrary  to  the  results  of  our  applications  made  to  still 
pools  of  water.  This  may  have  ])een  due  in  part  to  the  fact  that  there 
was  more  or  less  of  a  current  in  the  drain,  and  may  also  have  Ix^en 
due  to  the  use  of  an  especially  volatile  kerosene.  The  writer  is  now 
advising-  the  use  of  the  grade  known  as  lubricating  oil  as  the  result  of 
the  extensive  experiments  made  on  Staten  Island.  It  is  much  more 
persistent  than  the  ordinar}^  illuminating  oils. 

An  interesting  plan,  suggested  to  the  writer  ]>y  Mr.  W.  C.  Kerr, 
of  New  York,  in  conversation,  to  disseminate  oil  over  salt  marshes, 
was  that  of  putting  barrels  of  oil  in  the  marshes  in  winter  when  the 
ground  is  frozen  and  piercing  the  barrels  with  small  holes  so  that  the 
oil  will  escape  slowty  through  the  following  breeding  season.  The  best 
method  of  distributing  oil  on  the  surface  of  water  is  a  practical  ques- 
tion which  each  experimenter  is  apt  to  settle  for  himself.  The  Avriter 
has  adopted  the  plan  of  simply  pouring  the  requisite  quantity  of  oil 
upon  the  water  and  allowing  it  to  spread  by  itself,  which  it  does  in  the 
course  of  time.  The  Staten  Island  and  Summit,  N.  J.,  people  use  a 
spray  pump,  but  in  some  ways  this  seems  to  the  writer  not  perfectly 
satisfactory.  A  great  deal  of  kerosene  is  apt  to  be  wasted  and  the 
continuous  la^^er  of  oil  which  is  desirable  is  frequenth"  not  brought 
about.  The  Liverpool  School  of  Tropical  Diseases  advises  as  the 
result  of  the  Sierra  Leone  work  that  the  oil  can  be  best  applied  by 
smearing  the  pool  with  a  rag  iixed  to  the  end  of  a  stick  and  dipped  in 
a  pot  of  oil.  "  In  this  manner  a  num})er  of  pools  can  be  dealt  with  in 
five  minutes  at  the  expense  of  ver}'  little  oil." 

OTHER   LARVICIDES. 

Permanganate  of  potash. — Other  su])stances  have  been  experimented 
with.  Two  3^ears  ago  many  newspapers  contained  an  item  concerning 
the  use  of  permanganate  of  potash.  As  this  item  was  credited  to  the 
Public  Health  Journal  it  gained  a  great  deal  of  credence,  and  was 
afterwards  mentioned  in  an  interesting  article  by  Mr.  A.  C.  Weeks, 
in  the  Scientific  American.     The  published  note  read  as  follows: 

Two  and  one-half  hours  are  required  for  a  mosquito  to  develop  from  its  first  stage, 
a  speck  resembling  cholera  bacteria,  to  its  active  and  venomous  maturity.     The 


58 

instMt  ill  all  its  iiha.<**s  may  Ik*  iiiHtantly  kill(*<l  l»y  conta*-!  with  ininuto  quantitieH  of 
l»c*rnianj:aiuitr  »if  itnta^^li.  It  is  tlaiiind  that  1  j»art  of  this  Huht>taiK'e  in  1,500  of 
.solution  (listrihutrd  in  niof^juito  niarslu'H  will  iviuler  the  development  of  larvt-e 
inii>ossihK';  that  a  haiulfnl  of  pernian^anat**  will  oxidize  a  10-aere  Hwainp,  kill  itn 
eiiiliryo  innet-tM,  and  keep  it  free  from  or^'anic  matter  for  thirty  <layH,  at  a  cost  of  25 
r-ent^;  that  with  care  a  whole  State  may  he  kept  free  of  insect  j»ests  at  a  small  cost. 
An  iHicaci«»ns  method  is  to  scatter  a  few  <Tystals  widely  apart.  A  sin^de  pinch  of 
peniian^Miiatc  has  killed  all  the;:erms  in  a  1  ,(KM)-.jallon  tank. 

The  item  is  so  ()li\i()iisly  fidiciilous  upon  its  fac*'  tlnit  it  would  liiirdly 
seem  woitli  Nvliih'  to  make  any  attemp.  to  i-efiile  its  statements.  Nev- 
(Ttht  le>s.  it  has  heen  so  \vi(l(dy  read  thai  dcdiiiite  e.xpeiimentation 
seems  neci'ssary  to  set  the  matter  at  I'est.  The  unknown  author's 
iotioraneo  of  the  life  histoiy  of  moscjuitoes  in  the  oi)ernno-  sentence 
need  not  necessarily  imply  that  he  would  not  know  a  j_^ood  femedv  if 
lie  found  one.  (  ai'cfid  experiments  ^vcl•^^  imdertaken  hy  the  wfiter 
in  July.  iStKS,  with  various  strenoths  of  peiinanjj;anat4'  of  i)ot{tsh  in 
water  containino-  moscpiito  lai\  u'  froiu  one  to  six  days  old.  It  was 
foimd  that  small  amounts  of  the  chemical  liad  no  efl'ect  whatever  u])on 
the  laixa'.  which  were,  however,  killed  ]>y  usino- amounts  so  hirge  that, 
iust^'ad  of  using  a ''handful  to  a  lo-acre  swamp/'  at  least  a  waj^on 
load  woidd  have  U)  ]h\  used  to  accomplish  any  result.  Moreover,  after 
th(^  use  of  this  large  amount  and  after  the  larvni  were  killed,  the  same 
water  twenty -four  hours  later,  sustained  freshly-hat<*hed  mosquito 
larva?  perfectly,  so  that  (»ven  were  a  person  to  go  to  the  prohibitive 
expens(»  of  killing  moscjuito  larvte  in  the  swamp  with  permanganate 
of  potash,  th(i  same  tusk  would  have  to  be  done  over  again  two  days 
later. 

The  same  conclusion  was  sul)se(juently  reached,  after  careful  experi- 
ment, 1)V  Dr.  Lederle,  of  the  New  York  health  olHce,  and  ))y  the  Ital- 
ians (\dli  and  Casagran<li. 

I^ropr'nidni  '^mlxtinus. — A  munber  of  proprietary  and  secret  mix- 
tures rcH'onuniMuled  for  m()S(iuit()-l)ree(ling  pools  and  whi(di  have  been 
])ut  on  the  market  since  tin*  vvide-spread  interest  in  the  moscpiito  ques- 
tion has  spnuig  up  ha\ c  beiMi  tested  bv  the  writiM',  Init  none  have  been 
found  more  satisfactory  than  the  cheapest  jxdroleum  oil. 

Krjx I'fiiKiifx  of  (  'rll/  tiiid  ( 'iixiKji'dniVt.  The  most  extensive  s(n*ies  of 
expeiinsents  with  culicidal  mixtures  which  has  been  made  was  con- 
ducted by  the  lt;dians  (\dli  and  Casagrandi,  above*  referred  to.  They 
lia\'e  ta))ulate(l  in  tlu'  "Annali  d'  Igiene  Sperimentale.  Ivome  (\'(d.  IX. 
Fasc.  Ill,  lsi)l>,  ])p.  :il7-:)r):)),  the  results  of  exi)eriments  with  many 
>ul>stances.  Ueferring  to  petroleiuu,  th(\v  say  that  apart  from  the 
(piestion  of  \X\(\  expense,  which  outside  (d'  AmtM'ica  is  worthy  of  note, 
the  action  of  })etroleinn  in  destroying  mosipnto  larvie  is  not  always  to 
be  put  in  the  front  rank.     Their  con(dusions  ar«'  practically  as  follows: 

(1)  of  tlu' whole  jicriod  of  the  cycle  of  development  of  mos(|nit<K's  the  stagers  in 
whicli  they  are  most  easily  di'stroyed  are  th(>si'  of  larva'  and  of  iln-  aerial  iiios«piito, 

and  larv.e  are  most  eavi|\-  killed  iju'  \..iui<_'ei-  tlie\  are. 


59 

(2)  To  kill  tlu'  larva',  amon«;  imiiu'ntus  .Muh.Mtancos  oxiM^riinontc<l  \\illi,  Ihtn-  will 
nave,  ill  iUHR'a>iin«;  «)r(UT,  culiriilal  action:  (a)  Mineral:  Hiilphuroiis  (»xi<i»',  jKrinan- 
j;anate  of  i)otash  with  hydrochloric  acid,  coimnoii  Siilt,  iK)tii.sh,  aninionia,  carburet  of 
lime,  eorrosive  sublimate,  chloride  of  lime,  tlu'  bisuli)hites,  Hiilpliat*^  of  iron  or  cop- 
per, lime,  bichromate  of  potiish,  and  sodium  sulphit*'.  (b)  Orj^anic:  i»(^vders  of  the 
unexpanded  flowers  of  ('hrysanthemiim,  tobacco,  ix'troleum  and  oils,  formalin, 
creso.,  certain  aniline  colors  («rallot,  «rreen  malachite),  coal  tar.  Taking  into  account, 
however,  the  (h^-^e  necessary  to  kill  the  larva',  the  ])racticability  and  the  ]»rice,  all  of 
the  mineral  and  some  of  the  organic  substances  are  excluded,  and  there  remain  as 
available  the  vegetable  ])owders,  petroleum,  and  the  aniline  colors. 

(3)  To  kill  aerial  mosquitoes,  we  have  odors,  fumes,  or  gjuses.  Among  the  odors 
are  turpentine,  iodoform,  menthol,  nutmeg,  camphor,  garlic.  Among  the  fumeft 
are  tobacco,  chrysanthemum  powder,  fresh  leaves  of  eucalyptus,  qua.ssia  wood, 
pyrethrum  powder.  Among  the  gases,  sulphuric  oxide.  It  is,  however,  to  he  noted 
that  for  these  odors,  fumes,  or  ga.ses  to  exercise  their  culicidal  action  they  must  fill 
or  saturate  the  whole  ambient;  otherwise  they  produce  only  apparent  death,  or  at 
most  only  a  culicifugal  action,  which  sometimes  in  houses  may  be  useful  in  protect- 
ing man  from  being  bitten  by  mosquitoes,  and  preventing  the  latter  infecting  him 
when  they  have  sucked  the  blood  of  malarious  persons. 

(4)  The  problem  of  the  destruction  of  mosquitoes  is  experimentally  soluble,  but 
practically  it  will  only  be  so  when  economic  interests  desire  it.  In  this  latter  sense 
it  is  remarkable  that  the  old  larvicidal  use  of  petroleum  has  not  become  much  diffused 
in  those  places  where  it  is  very  cheap.  The  chrysanthemum  plants  might  l)e  grown 
on  a  large  scale,  this  making  the  malarial  place  itself  produce  that  substance  Avhich 
frees  it  of  the  mosquitoes  that  infest  it. 

(5)  The  opportune  season  for  killing  the  larvae  is  in  the  winter,  when  they  are  in 
least  numbers  in  the  waters  and  new  generations  are  not  born;  this  also  is  the  season 
for  their  destruction  in  houses,  for  they  come  here  for  a  warmer  abode.  Their  habits 
and  places  of  nesting  should  be  studied  to  this  end.  This  may  not  be  accomplished 
on  a  large  scale  as  easily  as  some  boast;  nevertheless,  after  the  treasures  spent  by 
nations  and  individuals  for  preserving  vines  and  vegetation  from  the  oidium,  the 
}ieronospora,  and  the  phylloxera,  we  may  hoj^e  that  something  may  be  done  for 
protecting  the  life  of  man  from  the  mosquitoes  of  malaria. 

It  will  be  noticed  that  they  really  exclude  from  further  consideration 
all  substances  except  vegetable  powders,  petroleum,  and  the  aniline 
colors.  By  vegetable  powders  they  refer  to  the  powders  from  the 
flowers  of  plants  of  the  genus  Pyrethrum,  and  their  experiments  upon 
the  aniline  colors  practically  center  upon  the  recommendation  of  the 
substance  already  referred  to  as  the  yellow  aniline  dye  which  the}'  call 
'•  Lar3'cith  TIT."  This  color  has  the  property  of  other  aniline  colors  in 
that  it  is  soluble  and  diffusible  in  water.  The  practice  recommended 
is  to  make  a  concentrated  solution,  which  is  poured  into  the  pool  or 
pond  to  be  treated.  Tt  is  said  l\v  the  authors  that  it  will  destroy  all 
insect  life  and  fishes,  but  is  harmless  to  warm-])looded  animals:  thus 
domestic  animals  may,  without  danger,  driniv  from  pools  being  treated. 

Just  what  "Larycith  III"  will  prove  to  be  and  whether  it  will  be 
available  for  use  in  this  countr}^  unfortunately  can  not  be  ascertained 
at  the  present  moment.  Correspondence  has  been  entered  into  with 
large  dye  firms  in  New  York  Avho  have  sent  abroad  for  information. 

Dr.  Ross,  in  his  article  in  Nature  of  March  29,  previously  referred 


60 

to,  says:  ''On  the  whole,  the  most  proniisint^  method  which  suggests 
itself  is  the  ein])l<>vin('nt  of  some  cheap  solid  material  or  ])owder  which 
dissolves  slowly,  which  kills  the  larva'  without  iiijurini^-  higher  animals, 
and  which  rend«'rs  small  })()ols  uniidiabitahle  for  the  larva?  for  some 
months.  \(^  for  instance,  a  cartload  of  such  material  would  suffice 
to  e\tirpat«'  the  larvae  over  a  square  mile  of  a  malarious  town,  the 
ic^nh  would  Itc  :i  large  gain  to  its  healthfulness.  Dr.  Fitdding-Ould 
has  lately  reported  favorably  on  tar.'' 

////'  <f/t(/  /As'  r(///tj)ot/n<7.s.  -Again,  in  the  re|)ort  of  the  Liverpool 
School  of  Tropical  Diseases  the  following  woi'ds  occur:  *'  Perhaps  more 
permanent  oil  than  UcM'osene  would  he  more  p<'iinanently  j'tt'ective. 
Fi-esh  tar  dro})ped  in  a  puddle  makes  a  film  like  that  of  oil  and  lias 
heen  faNorahly  i-eported  on.  (Quicklime  has  been  suggested,  and  all 
these  should  certainly  he  tried.'' 

The  writer  is  i-ather  at  a  loss  to  know  exactly  what  is  meant  )jy  the 
expressions  '*  fresh  tar"  and  "tai**  in  the  above  paragraphs.  He  has 
conducted  an  exp<'riment,  however,  with  a  substance  known  to  the 
trade  as  ''coal  tar,''  a  thick  viscid  liquid.  A  few  large  drops  of  this 
substance  AvcM'e  dropped  into  a  glass  vessel  containing  approximately 
2  (juarts  of  water  in  which  were  mort^  than  1(K>  full-gi*own  larva'  of 
Culex.  All  the  drops  but  one  sank  at  once  to  the  bottom,  the  last  one 
floating  upon  the  surface  for  some  time.  No  surface  film  seemed  to 
form  from  the  tar.  but  after  the  expiration  of  forty-eight  houi's  the 
water  was  found. to  be  more  oi-  less  impi'egnated  by  the  tar,  having 
turned  somewhat  darkei- ill  color,  while  the  odor  of  the  tar  was  per- 
eeptible.  At  the  expiration  of  live  days  nearly  all  the  Culex  larva^ 
were  dead;  1  had  succeeded  in  transformuig  to  ])upa,  and  5  or  (\  remained 
at  the  surface  enfeelded  and  dying.  Thus  more  than  IC)  per  cent  had 
been  killed.  In  the  meantime,  howex cr,  twenty-four  hours  after  the 
experiment  began.  >>  (\gg  mass(\s  wer«^  laid  on  the  surface  of  the  water 
by  outside  females  of  Tulex.  These  had  hatched  in  forty-eight  hours 
more,  and  on  the  Hfth  day.  altiiough  the  original  fuU-gi'own  lai'va' 
were  ])ractically  exterminated,  many  young  larva'  were  swarming 
activ<'ly  about  in  th<'  tar  watei".  They  continued  to  grow  and  to 
remain  a})})arently  ])ei-fectly  active  and  healthy,  although  the  odor  of 
the  tar  was  distinctly  ])erceptible  and  the  color  of  the  watei*  was  dark, 
and  cNcn  a  thin  oily  lilni  remained  o\'er  a  portion  of  the  sui'face. 

From  this  expeiiment  it  was  plain  that  the  killing  effect  of  the  tar 
in  the  ])i-e})aration  used  is  comparatively  fugitive,  and  it  was  next 
decided  to  test  some  of  the  coal-tar  products.  The  object  of  this  line 
of  experimentation  w.is  not  oidy  to  test  the  suggestions  of  the  English 
()})servers,  but  also  on  account  of  the  fact  that  as  almost  eveiy  com- 
nnmity  manufactures  its  own  illuminating  gas  it  was  considered  an 
easy  and  ]irobably  econominal  way  of  securing  a  mosquito  larvicide,  if 
it  should  pro\  e  to  be  ell'ecti\  e.     Coal  tai"  is  distilled  into  various gmdes 


61 

of  oil,  jiiul  two  of  the  licMvicr  of  tlicst*  o-mdcs  W(»n»,  used  in  tin*  sin*- 
c'(HMliiiu-  cxjH'rinuMits.  One  of  tlicso  was  cjilicd  ••creosote  oil,"  and  was 
}i  ratlu'i'  liiilil  oil  of  a  sjn'cilic  ^raxil y  of  LO^f)  at  <i(>"  l'\.  and  the  oilier, 
beaiini:-  no  name,  was  somewhat  lieaxier.  Tlie  e\i)eriiiients  wc^re  nec- 
essarily on  a  somewhat  small  scale.  Kiyhty  nearly  fidl-iirown  lar\;L' 
of  C>i/('.i'  sf fill ii/dii-s  and  (\  2>(  /•/ ui'lnms  were  placed  in  '.\  (|narts  of  water 
and  one-fourth  oimc(»  of  creosote  oil  was  poured  in  at  4.1;")  p.  m.  At 
5.45  IT  i)U})a'  and  'r,  ljirv;e  wei'e  left  ali\'e.  The  next  mornino-  at  \) 
o'clock  it  was  found  that  S  adults  had  issued  oN'cr  nij^'ht,  ])ut  all  had 
been  killed  ])y  the  creosote.  At  )) }).  m.  of  the  same  day.  twiMity-threc 
hours  after  tlu'  introduction  of  the  insecticid(%  all  larva' and  pupa;  were 
dead.  With  the  slightly  heavier  oil.  150  lar\  ;e  of  the  same  species, 
all  full  grown  or  nearly  so,  were  placed  in  '1  (piarts  of  water  and  three- 
sixteenths  ounce  of  the  oil  was  added  at  4.15  p.  m.  At  5.45  all  were 
dead  except  i^8  pupa?  and  about  30  larvae  The  next  morning*  at  9 
o'clock  it  was  discovered  that  10  {idults  had  issucnl  ovcm*  night,  but  had 
been  killed  before  flight  b}^  the  oil.  At  4.30  p.  m.  of  the  same  day  all 
the  larvae  were  dead,  but  10  pupte  w ere  still  active.  On  the  following 
morning,  at  D  o'clock,  forty-two  hours  after  the  ai)plication,  all  larvae 
were  dead  and  the  adults  had  issued  from  the  remaining  pup^e,  but 
had  been  caught  bv  the  oily  him  in  the  act  of  issuing  and  had  died 
upon  the  surface  of  the  water. 

Still  another  experiment  was  tried  with  pupae  only.  Two  hundred 
and  fifty  pupae  of  the  same  Culices  were  placed  in  3  (piarts  of  water 
and  one-fourth  ounce  of  creosote  oil  was  added.  Twenty  hours  later 
many  of  the  pupae  were  still  living,  but  thirty^-six  hours  from  the  time 
of  application  all  Avere  dead,  no  adults  having  issued.  A  check  experi- 
ment with  kerosene  was  carried  on  parallel  with  this  last  experiment 
with  creosote,  a*nd  it  was  noticed  that  the  action  of  the  kerosene  upon 
the  pupae  was  much  quicker,  all  dying  within  forty-five  minutes.  A 
few  young  larvae,  however,  in  the   same  jar  lived  for  several  hours. 

An  interesting  efiect  of  the  application  of  the  creosote  in  the  first 
two  of  these  experiments  was  that  it  seemed  without  doubt  to  hasten 
the  transformation  of  the  insect.  When  at  4.15  the  creosote  was 
poured  in  jars  1  and  2,  no  pupae  were  observed,  but  all  larvae  were 
full  grown  or  nearly  so.  After  fifteen  minutes  10  pupie  were  observed 
in  jar  2  and  5  in  jar  1.  Ten  minutes  later  15  were  counted  in  jar  2 
and  13  in  jar  1.  Twenty  minutes  later  there  w^ere  10  in  jar  2  and  22 
in  jar  1.  Fifteen  minutes  later  still  there  were  19  in  jar  2  and  22  in 
jar  1.  Thirty  minutes  later  there  were  17  in  jar  2  (2  having  died  in 
the  interval)  and  28  in  jar  1.  As  above  stated,  over  night  a  rumiber 
of  adults  issued,  10  in  jar  1  and  8  in  jar  2,  and  twenty-four  hours  later 
10  more  adults  issued  in  jar  1.  It  must  be  remarked  that  the  full- 
grown  larv»  struggled  violently  on  perceiving  the  uncomfortable 
presence  of  the  creosote,  and  as  they  were  just  ready  to  transform  this 


f^2 

\i(»lt'iit  stiiij^'-^^linj,'"  j'vidnitly  jissisl«'(l  in  (lie  ]n<*akin;jf  of  tlio  hirvjil  skin, 
h'a\  ill*,'"  tlir  pupa  han*.  This  traiisforiiiation  from  larva  to  j)uj)a  is 
liai'dly  as  inti'restinj^"  as  tlir  lapid  (l«'\ clopnn'iit  of  adults,  IS  of  which 
IssuimI  within  JiftiMMi  hours  after  tiaiisforiuation  to  pupa,  whereas 
prcN  iously  tin'  shoitcst  duiatioii  of  the  pupal  state  whieh  we  had 
ohsrrvcd  was  forty-cii^ht  hours.  It  looks  like  an  effort  of  Fiature  to 
j)rrp«'tuate  the  species  in  the  presence  of  a  uni(jue  enicrtrency. 

On  the  whole,  the  result  of  the  experiments  with  tur  and  tar  oils  wa.s 
ratln'r  unsatisfactory  as  compared  with  the  heavier  grades  of  kerosene. 
'I'he  etlect  of  the  tar  was  not  i)ermanent,  and  the  effect  of  the  ere()S(>te 
oils  was  not  as  rapid  as  tliat  of  kerosene,  and  the  writer  is  inclined  to 
tlu'  opinion  that  the  heavier  grades  of  kerosene  oils  are,  on  the  whole, 
preferable,  althougli  the  effect  of  the  creosote  oils  is  very  good,  and 
they  can  ])e  used  to  advantage.  lie  is  inclined  to  think  that  they  may 
})rovc  to  be  more  permanent,  although  not  quite  so  rapid  in  their 
effect,  than  the  lightei*  illuminating  oils. 

EUCALYPTUS  TREES. 


M  a(i 


Idition  to  the  use  of  eucalyj)tus  oil  on  the  skin  to  keep  mosquitoes 
from  )»iting,  the  growth  of  eucalyptus  trees  is  said  hy  certain  persons 
to  drive  mosquitoes  away,  and  trees  of  the  genus  Eucalyptus  have 
been  especially  recommended  for  planting  in  malarial  regions.  Mr. 
Alvah  A.  Eaton,  of  California,  wrote  us  in  ISiKS  that  in  portions  of 
California  where  the  ])lue  gum  occurs  no  other  remedy  need  ))e  sought 
for.  Further  than  that,  he  stated  that  no  matter  how  phMitif  ul  the  mos- 
quitoes, a  few  twigs  or  leaves  laid  on  the  pillow  at  night  would  secure 
perfect  inmninity.  The  same  3'ear  Mr.  W.  A.  Sanders,  of  California, 
sent  the  following  interesting  account  of  the  value  of  eucalyptus  trees 
in  answer  to  our  ]>u])lished  request  in  Insect  Life: 

1  have  the  larjre.^t  and  oldest  grove  of  trees  of  J'Jvcabjpfuff  glolnthis  in  this  part  of 
C'ahfornia,  and  liave  liad  fifteen  years  of  opportunity  to  study  these  trees  a>^  insect 
repellantt<,  and  deem  it  my  duty  t«»  respond  to  your  request  on  pt^e  268  of  Insect 
Life. 

Thirly-tiiree  years  a<ro  T  spent  a  i)ortion  of  one  summer  with  a  l>r.  MeConnell,  who 
had  just  returned  from  some  years  of  residence  among  the  Eucalyptus  forests  of  Aus- 
tralia. We  were  in  the  Seipioia  [SeijuoUi  xeiupcrvlrens)  forest  of  the  coast  region  of 
our  State.  The  mwsciuitoes  wi»re  so  bad  that  it  was  nearly  impossible  to  work  during 
days  when  there  was  no  wind.  The  doctor  assured  me  that  our  connnon  mos<]uito 
was  never  found  in  tlie  Australian  Eucalyptus  forests  and  swamj^s,  but  added,  There's 
a  "spotted  mosquito"  nearly  as  bad  there  in  some  places.  He,  not  l>eing  an  entomolo- 
gist, was  unable  to  tell  me  whether  the  "spotted  mosquito"  was  a  species  of  the 
genus  Culex,  or  of  some  allied  genus. 

The  doctor  l)eing  a  reliable,  close  ol)server,  I  determined  to  test  the  antimosquito 
qualities  of  the  Eucalyptus;  so  when  I  U'gan  to  improve  my  house  here  nineteen 
years  ago,  one  of  the  first  thintrs  I  did  wa.>^  to  get  a  lot  of  eucalyptus  seed  from  Aus- 
tralia and  plant  out  a  grove  oi  the  trees.  The  tallest  of  them  are  now  over  140  feet 
tall,  and  can  be  seen  for  20  miles  around.     My  house  stands  in  the  midst  of  these 


88 

ttvos.  ^\y  irri<;atiiiir  (lilcli,  a  du/cn  \rv{  uiWc,  of  .sliiir^ri,v|,  ,-iiiiriil,  runs  llnoii^'li  tlift 
jj:r()Vt>  iH'sidc  tlu'  lioiisc.  'I'licrr  li:is  lu-vcr  ;i  silij^h'  iiiostjiiito  l;irv:i  l«-cii  hmii  in  tlie 
ditch  from  whore  it  I'litt-rs  the  lirst  shadr  of  these  trees  to  where  it  eiiierj,M's  from  them 
200  yards  away,  whiK'  ahove  and  helow  mos(|iiito  larva-  are  itleiitiful— not  imme- 
diately behnv,  hut  some  hmitheds  of  yards  away,  where  the  water  stands  in  pools 
and  beeomes  siai^nant  amon*;  a  irrowth  of  black  walnuts  and  cottonwoods. 

My  live  st(X'k  pasture  in  this  tiud)er,  ^'oin^'  into  tlie  walnuts  and  back  again  under 
the  eucalyi)tus  shade  at  pleasure.  Fre(|uently  w  hen  the  c<»ws  come  up  at  night  they 
bring  a  swat'ui  of  mos(|uitoes;  occasionally  some  of  them  get  into  the  house,  but 
cause  us  so  little  auiioyanct'  that  we  scarcely  notice  them.  Uefoic  this  ditch  n-aches 
the  pAicaiypti  it  runs  through  a  jungle  of  "fence  bamboo"  { Arninh,  ui<icri>/)lii///a), 
where  the  mosijuitoes  are  so  bad  that  we  avoid  working  tiiere  except  on  the  windiest 
days.  And,  though  the  ditch  has  more  current  there,  the  larva;  of  mosciuitoes  are 
I)leiitiful  ill  the  water  till  it  reaches  the  Kucaly])tus  trec^s,  below  which  ])oint  none 
are  found  till  it  has  become  stagnant  away  below  them. 

People  who  have  camped  along  the  willows  of  Kings  liiver,  only  a  few  miles 
away,  have  come  here  ^ith  faces  so  blotched  and  swollen  from  nios(iuito  bites  as  to 
be  hardly  recognizable,  and  have  camped  in  the  shade  of  "Sanders's  gum  trees,"  as 
my  grove  is  popularly  called,  for  weeks,  and  declare  that  they  never  even  heard  a 
mosquito  sing  during  that  time. 

To  the  non-botiinical  reader  I  may  say  that  this  species  of  Eucalyptus  is  very  tender 
to  frost.  The  coldest  weatlier  ever  known  here,  19°  F.  above  zero,  killed  thousands 
of  them. 

Dr.  Nuttall  points  out  that  the  phuiting  ot  eiicalyptu.s  treefs  is  not  a 
sovereign  remedy,  from  the  fact  that  malaria  still  prevails  at  Tre 
Fontane,  outside  of  Rome,  in  spite  of  Eucalyptus  plantings.  The 
mere  planting  of  trees,  however,  is  undoubtedly  of  use  in  malarial 
districts,  since  it  will  modify  the  condition  of  drainage  of  the  soil. 
In  view  of  Mr.  Sanders's  strong  evidence  it  really  appears  that  plant- 
ing of  eucalyptus  trees  will  be  worth  while  in  certain  locations,  not 
entirely  (on  account  of  the  conflicting  and  not  thoroughly  satisfactory^ 
evidence)  for  mosquito  protection,  but  incidentally  for  this  use  as  well 
as  other  purposes. 

DRAINAGE    AND   COMMUNITY    AVORK. 

After  all,  the  best  of  the  means  which  may  })e  adopted  against  mos- 
quitoes will  always  consist  in  the  abolition  of  their  breeding  places. 
Small  pools  with  stagnant  water  can  be  treated,  but  it  is  a  great  deal 
better  to  drain  them  or  to  till  them  up.  Swamp  areas  nmst  sooner  or 
later  be  drained.  It  is  perfectly  obvious  that  the  sooner  this  is  done 
the  better  from  every  point  of  view,  not  only  from  that  of  human 
health  but  from  the  increased  value  of  real  estate  in  the  neighborhood 
and  from  the  practical  value  of  the  reclaimed  land  itself.  The  time  is 
coming,  aiKl  rapidly,  when  this  drainage  of  large  swamps  will  not 
remain  a  matter  which  concerns  the  individual  owner  of  the  land,  but 
one  for  town  or  county  action,  and  even  for  States.  The  report  of 
T.  J.  Gardner  on  the  policy  of  the  State  respecting  drainage  of  large 
swamps,  published  in  the  Report  of  the  Board  of  Health  for  New  York, 


64 

Alljjmy,  l.^^^^,  alth<ni<rli  uiitcdatiiijr  the  n'cciit  iiii|M)rtiiiit  in()s«jiiit()  dis- 
i-o\('i'i('s,  is  well  \V()i-tli  n-adiii*^  l»y  all  piihlir-niiiKlcd  persons,  and  tin 
annual  rrports  of  tin- St:itt' »;«M>l()irist  of  New  Jersey  for  1M«T  and  ISIKS, 
in  whicli  the  rrclamation  of  the  threat  I laekensiu-k  Meadows,  near  Jersey 
City,  Newark,  and  Klizal)etli,  N.  J.,  makes  interesting^  readin*:;  alon*^ 
this  lin«'.  \\\»rk  on  tin'se  marshes  has  actually  been  l)eg"un.  The 
solution  of  this  case  is  takinj^the  £orm  of  separate  action  hy  cities  and 
their  municipalities,  each  impro\  inu-  the  territory  within  it.s  corporate 
limits.  riu'  city  <d'  Newark  has  a  tract  of  4. ♦'»(»<»  a<-res  of  marsh  within 
its  limits:  deisey  C'ity  has  within  its  limits  '2J)Si\  acres  of  tide  marsh, 
and  Elizaheth  has  -JJuiS  acres.  The  three  cities,  therefore,  have  about 
8,T<M>  acres  of  the  :i7,<MM>  acres  lying-  between  Eliza}>eth  and  Haeken- 
sack.  'I'he  sanitaiy  imi)ortance  of  ie<laiming  these  lands  is  of  the 
cfreatest,  but  the  capal)ilities  of  th<'  imprc^vement  plans  are  attractinj^ 
attention  on  the  ])art  of  capitalists  and  business  men,  who  see  in  these 
tide  hinds  \aluable  sit<'s  for  manufacturing,  industrial,  and  commercial 
activity. 

Even  to  indi\i(lual  land  owners  of  a  comnjunity,  the  drainage  of 
swamps  and  the  conse(iuent  abolition  of  mos([uitoes  will  in  many  cases 
iKH'ome  well  worth  while.  The  writer  knows  of  a  town  in  New  Jersey, 
with  a  good  elevation,  within  easy  distance  of  New  York,  and  admirably 
adapted  forsununer  residences  of  New  Yorkers,  where  the  mosquitoes 
are  so  a))undant  as  to  prevent  the  rise  in  the  price  of  real  estate.  An 
examination  of  the  surrounding  country  has  convinced  him  that  if  the 
large  real  estiite  owners  were  to  clidj  togi'ther  they  might,  by  the 
exp(MKlitur(^  of  a  few  thousand  dollars,  largely  do  away  with  the  mos- 
(juito  plague.  Another  case  which  is  well  worth  s|X}citic  mention,  and 
the  truth  of  which  the  writer  will  vouch  for,  may  best  be  told  in  the 
words  of  a  correspondent,  printed  in  one  of  the  Flushing  papers  late 
in  ^larch: 

In  the  town  of  Stratford,  Conn.,  where  I  liave  resi(le<l  for  the  \ydsx  forty-tive  years, 
we  have  ])een  greatly  i>lagiied  hy  swarms  of  niosciuitoes,  so  great,  in  fa<.'t,  that  the 
"Stratford  nios<]iiito"  l)ecanie  a  well-known  eharaeteristic  of  Stratfoni.  We  have  in 
the  southern  part  of  our  town,  liordering  on  .the  sound,  several  acres  of  marsh  land 
or  mea<low,  which  w<juld  become  i>eri(xlically  overliowe<l  with  water  in  the  summer 
and  a  tremendoiLs  bree<iing  ground  for  mo8(]uitoes,  and  thiis  plague  to  the  town  con- 
tinue<l  until  about  l800-i>l,  when  a  party  from  Bridgeixjrt,  Conn.,  purchased  a  large 
section  of  the  meadows  and  l>egan  to  j)roteot  them  l>y  a  dike,  lx)th  on  the  nc^rth  and 
south  ends,  which  shut  out  the  water.  In  addition  tn  this,  numerous  drain  <iitches 
were  made,  which  helped  to  carry  the  water  away.  The  result  of  this  work  made 
the  land  i>erlectly  <iry  and  spongy,  so  that  after  a  rain  no  pools  collecte<i  on  the  sur- 
face of  the  meadow  an<l  prevente<i  the  creation  of  the  mostiuitoes.  The  transfonna- 
tion  wa«  so  remarkable  that  i>eople  outside  the  town  would  hardly  T)elieve  that  it 
had  iM^en  effecte<l,  and  a  year  or  two  hiter  the  town  vote<l  a  si>ecial  appropriation  oi 
$2, ()()()  to  tlie  party  who  undertook  to  huild  the  dike  and  ren<ler  the  meadows  nios- 
<|uito  proof.  It  had  also  the  effect  of  placing  on  the  market  a  large  tract  of  land 
elevated  from  the  sound  for  reisideuces,  and  as  manv  its  25  summer  reisideuces  have 


(if) 

been  built  upon  this  land  hoidcriiiL:  the  houihI,  hihI  an-  iiuTcaxiiijr  ra<li  year.  'I'licy 
are  free  from  nios(iuit()('s,H)  that  tin- operation  sbuws  tin-  ri-onoiuy  aii<l  llif  Ix-nclit 
that  will  result  ])y  usin<r  soiui'  mraus  for  flirninatin;;  tlu-  nios<iuito-l)n'*'(liiiK  pools. 

As  to  coinniuiiity  work,  we  must  not  fail  to  niontion  tho  iiitcn'stiiif^ 
fact  that  the  city  of  Winchester,  Va.,  is  reported  to  liave  passed  an  ordi- 
nance reciuirino-  property  hoUhM's  to  treat  drains  and  stut^Tiant  pools  of 
water  witli  kerosene  diirino-  tiie  siinnner  season.  Winchester  is  a  town 
of  high  elevation  and  has  for  a  long  time  enjoyed  a  reputation  among 
Virginians  as  a  cool  place  to  spend  the  summer.  Mos(piito(\s,  we  are 
told,  however,  made  their  appearance  there  a  few  years  ago,  with  the 
effect  that  simimer  visitors  became  fewer  and  fewer.  The  passing  of 
the  cit}^  ordinance  was  deemed  a  matter  of  public  policy  and  met  Avith 
general  approval.  Police  measures  of  this  kind  may  not  be  inadvis- 
able under  certain  circimistances.  Surely  in  such  instances  as  the 
Baltimore  case,  mentioned  in  previous  pages,  it  seems  entirely  appro- 
priate that  the  board  of  health  should  be  called  upon  to  enforce  kero- 
sene treatment. 
3949 5 


APPENDIX. 


AN    KAHI.IKK    ACCOl'NT    <>F    HIK     I.AKVA    OF    ANOPHELES. 

Just  as  this  lujiimscript  was  about  to  he  sent  to  the  print/or  the 
writer's  attention  was  called  to  a  pajHT  })y  F.  Meinert,  entitled  *'Die 
encephale  My»r<'lai"\ cr"  (Sui'  les  larves  encephales  des  Oipteres;  leurs 
UKeurs  et  leurs  inetanioi  piloses),  K.  l>anske  Videnskabernes  S<dskal)s 
Skrifter  ((\)penhatrcn),  iii.  pp.  H7:^-lim,  IMs.  I-IV  (l<SS(j),  in  which. 
anioriiT  other  ohservations,  he  ji^ives  a  ln'ief  stat<'iiient  concerninjj^  Ano. 
p}i«'lc>  w  hicli  is  sufficiently  int4»resting  to  translate: 

" AnnpJirli's. — In  the  •Observations  d'Histoire  Naturelle'  of  Joblot 
one  tinds  a  de.scrii)tion  of  this  larva.  *' Description  of  a  new  tish.'' 
which  is  rather  insignificant,  and  a  drawinj^^  which  is  not  badly  done. 
The  larva  drawn  by  Brauer  as  Anopheles  is  a  larva  of  Dixa,  and  those 
reported  )>y  Fischer  (rWaldheini  as  (\  rhirf(j<  r  wrv  lar\a*  and  nymphs 
of  the  genus  Corethra,  while  his  nymph  is  a  Tanypus.  and  his  tiy  an 
Ano})heles.  Aside  from  this,  (ierkc  has  ))ri«'tly  mentioned  this  hirva 
in  his  papi'r  entitled  'On  the  metamorphoses  of  the  dipterous  genus 
Dixa,'  page  166. 

•'The  larva  of  Ano])heles  lives  in  still  waters  oi-  in  a  weak  current 
with  a  rich  vegetation,  in  wooded  or  unwooded  regions.  It  does  not 
like  the  shade  of  great  trees,  but  seeks  the  sun  and  the  light,  as  is 
indicated  })y  its  fresh  green  color.  Tt  does  not  hibernate,  but  in  mild 
seasons  it  is  found  in  a  half-grown  condition  by  the  end  of  March.  In 
July  or  a  little  latter  in  the  course  of  a  summer  the  second  generation 
of  the  full-grown  larva'  are  found,  and  in  1SS2,  a  year  when  the*  spring 
was  very  forward,  the  writer  found  at  the  end  of  October  small  larvte 
which  certaiidy  belonged  to  the  third  generation;  but  it  was  not  to  be 
supposed  that  these  larvsv  Avould  beccmie  full  grown,  since  as  they  live 
at  the  surface  of  the  water  the  tirst  film  of  ice  would  kill  them. 

"The  larvjv  hold  themselves  at  the  surface  of  the  water,  where  they 
float  with  the  extremity  of  the  abdomen  turned  toward  the  bank  or 
toward  the  plants  which  cover  the  surface.  The  larva  is  stretched  out 
in  the  water  with  the  respiratory  tube  at  the  surface.  The  larger  })art 
of  the  alnlomen  and  posterior  part  of  the  thorax  are  submerged,  only 
a  little  portion  of  the  prothorax  emerging.  The  head  is  under  water. 
The  long  hairs  with  which  {\w  ))ody  of  the  female  is  provided  on  the 
sides,  on  the  metathorax.  and  the  tirst  three  segnuMits  of  the  abdomen 
are  of  great  assistance  to  it  in  maintaining  a  fixed  i)ositiofi.  It  rests 
often  for  a  long  time  immovable  and  oidy  occasionally  changes  its 
location.  Its  mo\  (Miients  denote  a  certam  apathy  or  indolence,  but  at 
the  same  tinu^  nuuh  prudence  aiid  apprehension.      WinMi   it  moves  it 


67 

movos  rapidly  and  dives  to  tho  bottom  of  tho  wator.  Rccovcrinii  from 
its  fritifht,  it  risos  obliquoly  to  the  surfaee. 

"Just  as  with  the  lar\;e  of  Culcw,  the,  lar\a'  of  AMoi)h('l('s  li\  <•  ii|>oii 
orgaiiie  microseopie  particles  wliicli  Hoat  upon  the  water,  and  which  are 
brought  into  the  mouth  by  the  moN'ements  of  the  rotatory  oryfans. 
These  organs  are  nuich  mon^  deyeloped  tlian  with  th(^  larya'  of  Culex, 
and  while  they  serye,  like  the  former,  as  a  brush  or  sieve  to  strain  th(^ir 
food  the  larva^  of  Anopheles,  like  those  of  Siimdium,  holdino-  the  head 
stretched  forward,  use  them  to  agitate  th(^  water.  The  larvii?  of 
Anoi)heles  present  this  peculiarity,  that  in  producing  these  currents, 
which  they  do  th(^  greater  part  of  the  day,  they  lie  upon  the  belly 
with  the  under  pai't  of  the  head  turned  upward.  This  rotation  of  the 
head  is  executed  with  thegrinitest  rapidity:  and  scarceh^,  for  example, 
have  the  larva>  come  to  the  surface  to  float,  when,  b}^  a  rotation  of  the 
head  upon  its  longitudinal  axis,  it  is  turned  bottom  side  upward  and 
commences  to  agitate  the  surface  of  the  water.  This  agitation  is 
undou])tedh"  for  the  purpose  of  drawing  floating  oV)jects  surely  and 
completely  into  the  orifice  of  the  mouth.  This,  however,  is  not  neces- 
sar}',  for  often  one  sees  the  larva  with  its  head  working  in  normal 
position,  mouth  organs  ])elow,  but  in  general  they  do  not  remain  in 
this  position  for  a  long  time,  and  it  is  only  after  having  turned  the 
head  upward  that  the}^  seem  to  work  con  amove. 

'"As  a  rule  the  larvae  seek  their  nourishment  while  they  are  floating 
at  the  surface,  but  at  other  times  they  descend  two  or  three  inches 
under  the  water.  They  can  rest  several  minutes  in  this  position  with 
the  head  below,  after  which  they  come  to  the  surface  again." 

This  account  shows  that  ]Meinert  knew  the  larva?  very  well,  and  one 
can  only  regret  that  he  did  not  describe  the  eggs  and  the  pupae. 

THE     MALARIAL    EXPEDITION    OF    THE    LIVERPOOL    SCHOOL    OF    TROPICAL 

MEDICINE. 

This  interesting  and  most  valuable  report  was  known  to  the  writer 
only  by  brief  newspaper  notes  until  the  present  bulletin  had  reached 
page  proof — too  late  to  insert  in  proper  place  several  important  obser- 
vations made  b}^  Ross,  Annett,  Austen,  and  Fielding-Ould.  To-day 
(August  13)  it  has  reached  him  in  Volume  II  of  the  Thompson  Yates 
Laboratory  Reports  (University  Press  of  Liverpool,  1900),  and  he  is 
glad  of  the  opportunity  to  add  the  following  paragraphs  quoted  from 
its  pages: 

8.    METHODS    FOR    ASCERTAINING    DEFINITIVE    HOSTS. 

The  long  researches  of  one  of  us  in  India,  followed  by  those  of  Koch,  Daniels,  and 
the  Italian  investigators,  have  given  us  a  very  exact  knowledge  of  the  life  history  of 
the  Hsemama^bidse  in  gnats,  and  have  shown  us  how  to  detect  them  in  the  insects 
with  ease  and  certainty.  It  has  been  noted  that  in  inhospitable  species  of  gnats  the 
ingested  parasites  perish  within  the  stomach  cavity,  whereas  in  hospitable  species 
the  zygotes  escape  from  that  cavity  and  develop  in  the  tissues,  ultimately  giving  rise 
to  blasts  which  are  found  in  the  juices  and  salivary  glands  of  the  insect.    *    *    * 


68 

15.    BIONOMK-S    «tK    ANOPHELES    LARVJ?:. 

We  ma<U«  the  fulli.wiii^'  nhservatioiiH: 

(1)  K(j(f}<.--T\\vrn-  AW  It^Htl-xfuijHfl,  Vikeiho^  i){  Atwph4'h>nAy»(}r\e<\  in  India.  They 
rtpjH'ar  to  U*  laid  sinjjly  uii  water,  hut  eohere  hy  tlieir  eixls.  forming  typieal  triangu- 
hir  j>atterns,  and  aln*  atlhere  to  floating  ohjeet.**,  the  nideK  of  the  vessel,  etc.  We 
ohnervtMl  no  factH  imlieating  that  they  are  ever  laid  on  wjlid  purfaee**.  In  vitro  they 
take  alMiut  twenty-four  hours  to  hatch,  l>ut  the  iK'ri(Ml  is  |>rohahly  nuich  s}njrter  in 
l.uddles. 

(2)  Ihiralinii  uf  hinol  Miujt . — Thi.s  dejtends  on  tenifKirature  an«l  auHHUit  of  fiMwi. 
Under  natural  conditions  it  may  prohahly  U'  only  three  or  four  days,  hut  underunfa- 
vonilde  conditions  (cold,  overcrow* ling,  ahsence  <»f  focwl)  it  may  certainly  extend  to 
Weeks.'  Tlu-re  are  reasons  for  thinking  that  development  is  much  luLstene*!  hy 
bright  weather,  in  «.rd<'r  to  »'nal)l»'  tin-  iinag(.  to  hatch  out  In-fon*  desiccation  of  the 
containing  )>udille. 

(3)  IumkJ. — The  larvji-  were  fre<iuently  watclu'<l  floating  on  the  surface  and  feeding 
on  filaments  of  waterwee*!,  amongst  which  they  often  entangle  themselves.  On  dis- 
section the  intestine  was  found  crammed  with  these  filaments.  It  wa.s  ohserve<l  that 
JM  vitrit  the  larva'  scarcely  grow  in  size  unless  they  are  given  large  cjuantities  of  water- 
wee<l,  which  they  <lispose  of  very  rapidly.  On  the  other  hand,  larvte  were  often 
cauglit  in  puddles  in  which  no  green  vegetation  could  }>e  seen.  They  may  eat  other 
fo(Ml,  l)ut  it  would  seem  as  if  waterwee<ls  constitute  their  favorite  diet.  It  was  also 
note<l  that  they  obtain  shelter  among  these  wee<ls  from  the  current  running  through 
the  j>ools  during  or  after  rain. 

(4)  Enemies. — No  oV>servations  could  l»e  made  under  this  head,  Init  we  often  found 
many  frogs  and  tadpoles  in  the  ]>reeding  ]»ools.  apparently  living  at  jK^ace  with  the 
larvae. 

(5)  Effects  of  desiccation. — During  most  of  our  stay  in  Freetown  lieavy  showers  fell 
several  times  a  day,  so  that  the  larvje  couM  live  secure  from  desiccation  in  all  but 
the  most  evanescent  puddles.  In  September,  however,  there  was  a  complete  break 
in  the  rains,  lasting  three  days.  A  lai-ge  num])er  of  the  pools,  even  many  of  those 
containing  waterwee<l,  and  those  fed  by  sjjrings  during  rain,  dried  up  completely. 
The  question  whether  the  larva*  had  the  jMiwer  of  living  in  the  nnid  at  the  bottom  of 
the  jM>ols  couM  now  Ik^  teste<l  by  direct  observation.  The  bri'ak  in  the  rains  was 
followtMl  by  heavy  showers,  which  immediately  refille<l  all  the  puddles.  Hail  the 
larva'  contimied  to  exist  in  the  mud,  they  would  now  have  emerge<l  again.  As 
regards  the  pud<lles  in  which  the  mud  had  completely  drie<l,  this  wa.s  not  the  c^ase. 
No  larvje  at  all  were  f()und  in  them  for  at  least  two  days  after  the  rain  had  refilled 
them.  After  that  interval  larva-  again  apj>eared,  ]>ut  they  were  very  small  ones, 
evidently  just  hatched  from  the  egg.  On  the  other  hand,  it  wiu<  frequently 
observe<l  that  if  the  mud  di<l  not  l>ecome  completely  dry,  the  larva*  would  emerge 
into  active  existence  after  another  shower.  These  observations  were  supportiil  by 
some  exjxiriments  in  vitro,  an«l  we  therefore  conclude  that  the  larva*  can  withstand 
partial,  though  not  complete,  desiccation. - 

(6)  The  same  jtuddh's  roihstinifh/  ornipicd. — We  liave  suggestetl  (paragraph  13)  that 
the  j>osition  of  the  breeding  j)ools  may  change  acconling  to  the  seasons,  but  while  we 
were  in  Frt*etown  there  was  no  change  of  season,  and  we  generally  found  Aiiopheles 
larva*  in  the  sann*  jiuddle,  nanu*ly,  in  those  which  were  suital>le  for  them.  Thus,  of 
two  jaiddles  lying  clo.^e  together,  one  Mould  never  contain  larva*  and  the  other 
would  always  contain  them.     The  exi)lanation  of  this  probably  is  that   the  larva* 

*  One  of  us  kept  Culex  lar\'}e  alive  ft>r  two  months  in  a  Inittle  in  the  cold  weather  in. 
India. 

Hhie  of  us  reared  adults  from  full-grown  larva*  kept  on  <lamp  blotting  pajier  (in 
India),  but  found  that  the  y»>ung  larva*  die<l  when  kept  under  these  conditions. 


69 

perish  in  the  unsuitable  pools,  or  that  the  adults  gemTally  return  to  tlie  same  ]mk)1s 
in  order  to  lay  their  v^i;i*.  It  seems  likely  that  the  adults  generally  lay  their  eggs  in 
the  pools  in  which  they  themselves  were  bred,  and  that  the  insects  thus  learn  by 
experience  the  places  most  suitable^  for  them. 

(7)  Detection. — It  is  easy  to  overhjok  AnojtJiehs  iarvje  unless  they  are  >i«';irched  for 
in  a  bright  light. 

(8)  Piipie. — The  })uj>a'  of  Aii<q>}u'le>i  seen)  to  be  smaller  than  those  of  tlu';  coiii- 
moner  species  of  Cuh'x.  They  reijuiie  about  forty-eight  hours  to  reach  maturity  in 
vitro;  perhaps  less  in  natural  conditions. 

10.    BIONOMICS    OF    ADI'LT    ANOPHELES. 

(1)  Ilatcliing. — The  adults  generally  hatch  out  in  the  evening;  but  their  exit  seems 
often  to  depend  on  the  meteorological  conditions  of  tlie  moment,  an«l  appears  to  be 
delayevl  by  rainy  and  windy  weather. 

(2)  Food. — They  can  easily  be  kept  alive  in  glass  cages,  test  tubes,  Ijottles,  etc. 
We  kept  some  in  this  manner  for  a  fcjrtnight,  and  could  doubtless  have  kept  them 
longer  if  we  had  wished  to  do  so.  We  are  able  to  confirm  Bancroft's  statement  (18) 
that  gnats  feed  on  bananas;  but  they  seem  to  prefer  the  fresh  fruit.  During  the  day 
the  insects  remained  at  rest  on  the  walls  of  the  cage,  but  in  the  evening  l)egan  to 
fly  about  and  to  walk  over  the  fruit,  plunging  their  proboscis  into  it  in  many  places, 
so  that  the  banana  was  sometimes  covered  with  gnats,  both  male  and  female.  They 
also  drink  water  frequently,  and  each  can  often  be  seen  to  be  distended  with  the 
fluid.  Raw  meat  was  offered  to  them,  l)ut  they  could  not  be  observed  to  touch 
it.     Earth  i)laced  at  the  bottom  of  the  cage  seems  to  be  suitable  for  them. 

According  to  the  accounts  of  the  soldiers  at  Wilberforce,  they  bite  almost  entirely 
in  the  evening  and  night,  but  have  been  known  to  feed  on  men  during  the  day. 
They  can  certainly  be  fed  on  men  artificially  during  the  daytime,  simply  by  placing 
them  in  test  tubes  and  then  aj^plying  the  mouth  of  the  tube  to  the  skin.  The  stom- 
ach can  be  observed  to  become  distended  in  from  one  to  two  minutes  or  more;  after 
which  the  insect  continues  to  suck,  but  commences  to  evacuate  by  the  anus  serum 
containing  a  small  jjercentage  of  red  corpuscles.  Cule.r  voids  only  a  clear  fluid  under 
the  same  circumstances.  The  insects  sometimes  continue  sucking  like  leeches  for 
five  or  ten  minutes,  voiding  blood  all  the  while;  but  at  other  times  soon  withdraw 
the  proboscis  and  then  try  another  spot.  It  was  noted,  however,  that  Anopheles 
fed  in  this  manner,  even  after  they  had  remained  sucking  for  five  or  ten  minutes, 
never  showed  any  great  distension  of  the  abdomen;  while  the  contents  of  the  stom- 
ach still  remained  for  some  time  transparent  and  red  as  seen  through  the  scales  of  the 
living  insect.  Moreover,  in  these  cases  the  meal  was  generally  digested  or  voided 
within  about  twenty-four  hours. 

On  the  other  hand,  AnopJieles  which  had  fed  themselves  under  natural  conditions 
generally  presented  a  very  different  appearance.  They  were  enormously  distended; 
w  hile  the  contents  of  the  stomach  were  thick,  opaque,  and  black,  and  sometimes  did 
not  disappear  for  three  days.  The  only  inference  is  that,  under  natural  conditions, 
the  insects  w^hich  can  manage  to  do  so  gorge  themselves  over  and  over  again  during 
the  night — probably  from  the  same  subject. 

(3)  Propagation. — We  also  observed  that  while  naturally  fed  gnats  invariably  laid 
eggs  after  two  or  three  days,  those  which  had  been  bred  from  the  larvae  in  captivity, 
and  had  then  been  isolated  and  fed  in  test  tubes,  never  did  so,  although  before  being 
isolated  they  had  long  been  in  company  with  males.  The  inference  is  that  fertiliza- 
tion takes  place  only  after  the  female  has  been  fed. 

We  noted  also  that  in  a  cage  where  many  male  and  female  gnats,  Cidex  and  A  no- 
pheles,  were  kept  together  for  weeks  eggs  were  never  laid,  although  the  insects  were 
fed  as  described  on  bananas,  and  the  cage  contained  water  for  them  to  lay  their  eggs 
in.     It  seems,  then,  that  a  meal  of  l)lood  is  necessary  before  fertilization. 


70 

r^Mtly,  Nvc  <)l>w*rviMl  tliat  previously  U'*\  iiinl  fertilized  inneetH  would  lay  a  neeoutl 
l)atth  of  rt^gs  after  a  se<-()U<l  nieail  of  I>1c»«m1  without  a  neeoud  fertilization,  Imt  never 
laid  aK*«»»nd  l»at«'h  «>f  i-jrj^  without  a  st-cuiid  iiu-al  <tf  1»1<kmI.  That  is,  one  fertiliza- 
tion .viullic-eH  for  s«'\«'r:il  1  >;itel u*s  of  «'^';:.<,  ImM  one  niral  of  Idood   for  oidy  one  hatch  of 

Tlu'se  ol>sfrvations  arr  wlioliy  in  lui-ord  with  the  resuUs  «tf  the  ijrolonj^tMl  study  of 
many  kinds  of  gnats  nia<h'  in  India  hy  oiu*  of  us;  and  it  thfrefort*  seiMns  likrly  tliat 
tin*  foll.iwin},'  law  is  likely  to  hold  l'oo.I  f..r  the  Cnlir'nl:,  which  f»-cd  on  men,  at  l<-ast 
for  tlu*  commoner  species. 

Althou^di  these  irnats  can  live  indelinilely  on  iiiiii  and  iwrhaps  jnices  of  j)lants,  the 
female  re«|nires  a  meal  of  hlood,  iMtth  for  fertilization  an<l  for  the  develo]>nient  <»f  her 
o\a.      In  other  \sords,  tln'  ins«'cls  need  hl<»od  for  the  j»ri)pajration  of  their  species. 

\\\ 1  was  ne\er  I'onnd  in  male  Cn/irti/.i  in    P'reelow  ii,   according'  with  the  jreneral 

law. 

(4)  J/aitiifs. — The  lar;je  majority  of  Aiiojthrlis  <-aught  hy  us  in  dwellinjrs  were 
females  whiih  were  generally  much  gorged,  and,  if  fed  at  all,  were  invariahly  fertil- 
ized; in  other  words,  the  males  an<l  unfe<l,  or  only  slightly  fe<l,  females  do  not  gen- 
erally remain  in  the  houses  during  the  daytime,  or  if  they  <lid  remain,  kejjt  in  the 
roofs  or  other  dark  jdaces  where  they  were  little  ohserved.  On  the  whole,  we  think 
that  only  tho.^e  females  which  are  so  gorged  that  they  can  not  Hy  far  remain  in  the 
houses  during  the  <lay.  AVe  oliserved  that  if  a  cage  full  of  .l/*oy>A///.s  wa^  disturl)ed 
in  tlu-  daytime,  the  insects  always  struggle<l  toward  the  light  as  if  to  fly  out  from 
the  windows,  ami  several  which  escaped  fronj  the  e^iges  actually  did  s<».  On  one 
occasion  a  large  numlK*r  escape<l  from  their  cage  during  the  night  in  the  rooms  <tccu- 
pied  hy  one  of  us;  none  of  them  could  he  stH'U  next  morning. 

Yet  we  may  1m*  (juite  sure  that  lM>th  the  males  and  the  uufe<l  females  haunt  the 
houses  during  the  night.  The  invariahly  fertilized  conditions  of  the  gorged  females 
caught  in  the  houses  show  that  the  males  must  ln'  present  in  tiie  houses  when  the 
females  feed,  sinci'  the  latter  are  often  so  much  disten<ied  after  feeding  that  they  are 
oiniously  unwilling  to  fly  even  a  few  feet  from  the  1h*<1  (»f  their  victim;  in  other 
words,  fertilization  nuist  take  i)lace  within  the  houses.  The  nnfe^l  females  must,  of 
course,  resort  to  human  ha])itations  during  the  night  in  order  to  o])tain  their  food 
at  all. 

These  facts  would  seem  to  indicate  that  in  Freetown  in  the  rainy  si^ason  the 
AiiDjtht'Jex  resort  to  the  houses  during  the  night,  hut  that  all  except  thegorge<l  females 
liv<^  elsewhere  during  the  daytime — po.ssihly  sleep  in  the  trees  and  shruhs.  The 
j)oint  is  ot'  interest  as  tending  t<»  show  that  large  muu]>ers  of  Aiiophtlrs  may  he  pre.^nt 
in  a  dwelling  during  the  night,  without  it  heing  easy  to  And  them  during  the  <lay. 

It  should,  however,  he  added  that  in  India  males  and  unfed  females  were  often 
found  in  the  houses  in  large  numbers  )»y  one  of  us.  Possibly  different  sj^eies  have 
different  habits  in  this  respect. 

Several  ol<l  residents  of  the  country  inf(»rme(l  us  that  gnats  are  usually  \»'ry  preva- 
lent in  the  presence  of  nuich  vegetation — i'sj>ecially  long  >;rass  and  undergrowth. 
Though  it  is  diflicult  to  see  how  such  can  favor  the  larxa',  we  can  understand  that 
nuich  vegetation  can  shelter  the  a<lults  of  certain  sjx'cies,  which  may  even  ft»e<l  on 
particular  kin<ls  of  plants  when  they  can  not  obtain  blo(»d,  and  may  conse<juently 
find  it  easier  to  live  where  these  jilants  afford  them  both  food  and  shelter  than  else- 
where. It  must  also  be  ri'inendn'red  that  gnats  can  certaiidy  bite  birds  and  other 
mammalia  lM'.<ides  man;  and  that  such  are  apt  to  congregate  where  there  is  nmch 
vegetation.  ( )n  the  whole,  then,  there  is  nothing  improbable  in  the  idea  that  the 
Freetown  Aiinjiluhs  should  live  outsi<le  the  houses  in  the  daytime. 

o 


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